<XBRL>
<?xml version="1.0" encoding="us-ascii"?>
<!-- Created by Merrill Corporation -->
<!-- Generated by Fujitsu Interstage XWand B0160 -->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink">
  <link:roleRef roleURI="http://www.wfscorp.com/role/CashFlows" xlink:type="simple" xlink:href="int-20111231.xsd#CashFlows" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/BalanceSheet" xlink:type="simple" xlink:href="int-20111231.xsd#BalanceSheet" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/StatementOfIncome" xlink:type="simple" xlink:href="int-20111231.xsd#StatementOfIncome" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/StatementOfShareholdersEquityAndComprehensiveIncome" xlink:type="simple" xlink:href="int-20111231.xsd#StatementOfShareholdersEquityAndComprehensiveIncome" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/StatementOfShareholdersEquityAndComprehensiveIncomeCalc2" xlink:type="simple" xlink:href="int-20111231.xsd#StatementOfShareholdersEquityAndComprehensiveIncomeCalc2" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureDebtDetails" xlink:type="simple" xlink:href="int-20111231.xsd#DisclosureDebtDetails" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureCommitmentsAndContingenciesDetails2" xlink:type="simple" xlink:href="int-20111231.xsd#DisclosureCommitmentsAndContingenciesDetails2" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureCommitmentsAndContingenciesDetails" xlink:type="simple" xlink:href="int-20111231.xsd#DisclosureCommitmentsAndContingenciesDetails" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureDebtDetails2" xlink:type="simple" xlink:href="int-20111231.xsd#DisclosureDebtDetails2" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureIncomeTaxesDetails" xlink:type="simple" xlink:href="int-20111231.xsd#DisclosureIncomeTaxesDetails" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureIncomeTaxesDetails2" xlink:type="simple" xlink:href="int-20111231.xsd#DisclosureIncomeTaxesDetails2" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureNatureOfBusinessAcquisitionsSignificantAccountingPoliciesAndRecentAccountingPronouncementsDetails" xlink:type="simple" xlink:href="int-20111231.xsd#DisclosureNatureOfBusinessAcquisitionsSignificantAccountingPoliciesAndRecentAccountingPronouncementsDetails" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureNatureOfBusinessAcquisitionsSignificantAccountingPoliciesAndRecentAccountingPronouncementsDetails3" xlink:type="simple" xlink:href="int-20111231.xsd#DisclosureNatureOfBusinessAcquisitionsSignificantAccountingPoliciesAndRecentAccountingPronouncementsDetails3" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosurePropertyAndEquipmentDetails" xlink:type="simple" xlink:href="int-20111231.xsd#DisclosurePropertyAndEquipmentDetails" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureGoodwillAndIdentifiableIntangibleAssetsDetails2" xlink:type="simple" xlink:href="int-20111231.xsd#DisclosureGoodwillAndIdentifiableIntangibleAssetsDetails2" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureDebtDetails2Calc2" xlink:type="simple" xlink:href="int-20111231.xsd#DisclosureDebtDetails2Calc2" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureShareholdersEquityDetails5" xlink:type="simple" xlink:href="int-20111231.xsd#DisclosureShareholdersEquityDetails5" />
  <link:roleRef roleURI="http://www.wfscorp.com/role/DisclosureNatureOfBusinessAcquisitionsSignificantAccountingPoliciesAndRecentAccountingPronouncementsDetailsCalc2" xlink:type="simple" xlink:href="int-20111231.xsd#DisclosureNatureOfBusinessAcquisitionsSignificantAccountingPoliciesAndRecentAccountingPronouncementsDetailsCalc2" />
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/StatementOfShareholdersEquityAndComprehensiveIncomeCalc2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:label="ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:title="ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProfitLoss" xlink:label="ProfitLoss" xlink:title="ProfitLoss" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:to="ProfitLoss" xlink:title="calculation: ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest to ProfitLoss" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:label="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:title="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:to="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:title="calculation: ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest to OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:title="OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:to="OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:title="calculation: ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest to OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" order="3.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/CashFlows">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetCashProvidedByUsedInContinuingOperations" xlink:label="NetCashProvidedByUsedInContinuingOperations" xlink:title="NetCashProvidedByUsedInContinuingOperations" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:label="NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:title="NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInContinuingOperations" xlink:to="NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:title="calculation: NetCashProvidedByUsedInContinuingOperations to NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProfitLoss" xlink:label="ProfitLoss" xlink:title="ProfitLoss" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:to="ProfitLoss" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivitiesContinuingOperations to ProfitLoss" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:label="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:title="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:to="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivitiesContinuingOperations to AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DepreciationAndAmortization" xlink:label="DepreciationAndAmortization" xlink:title="DepreciationAndAmortization" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="DepreciationAndAmortization" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to DepreciationAndAmortization" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:label="ProvisionForDoubtfulAccounts" xlink:title="ProvisionForDoubtfulAccounts" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="ProvisionForDoubtfulAccounts" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to ProvisionForDoubtfulAccounts" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="ShareBasedCompensation" xlink:title="ShareBasedCompensation" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="ShareBasedCompensation" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to ShareBasedCompensation" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="DeferredIncomeTaxExpenseBenefit" xlink:title="DeferredIncomeTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="DeferredIncomeTaxExpenseBenefit" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to DeferredIncomeTaxExpenseBenefit" use="optional" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossUnrealized" xlink:label="ForeignCurrencyTransactionGainLossUnrealized" xlink:title="ForeignCurrencyTransactionGainLossUnrealized" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="ForeignCurrencyTransactionGainLossUnrealized" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to ForeignCurrencyTransactionGainLossUnrealized" use="optional" order="5.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_GainLossOnInvestments" xlink:label="GainLossOnInvestments" xlink:title="GainLossOnInvestments" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="GainLossOnInvestments" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to GainLossOnInvestments" use="optional" order="6.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherNoncashIncomeExpense" xlink:label="OtherNoncashIncomeExpense" xlink:title="OtherNoncashIncomeExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="OtherNoncashIncomeExpense" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to OtherNoncashIncomeExpense" use="optional" order="7.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="IncreaseDecreaseInAccountsReceivable" xlink:title="IncreaseDecreaseInAccountsReceivable" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInAccountsReceivable" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInAccountsReceivable" use="optional" order="8.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="IncreaseDecreaseInInventories" xlink:title="IncreaseDecreaseInInventories" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInInventories" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInInventories" use="optional" order="9.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidExpense" xlink:label="IncreaseDecreaseInPrepaidExpense" xlink:title="IncreaseDecreaseInPrepaidExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInPrepaidExpense" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInPrepaidExpense" use="optional" order="10.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="IncreaseDecreaseInOtherOperatingAssets" xlink:title="IncreaseDecreaseInOtherOperatingAssets" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInOtherOperatingAssets" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInOtherOperatingAssets" use="optional" order="11.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInOtherNoncurrentAssets" xlink:label="IncreaseDecreaseInOtherNoncurrentAssets" xlink:title="IncreaseDecreaseInOtherNoncurrentAssets" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInOtherNoncurrentAssets" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInOtherNoncurrentAssets" use="optional" order="12.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="IncreaseDecreaseInAccountsPayable" xlink:title="IncreaseDecreaseInAccountsPayable" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInAccountsPayable" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInAccountsPayable" use="optional" order="13.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInCustomerDeposits" xlink:label="IncreaseDecreaseInCustomerDeposits" xlink:title="IncreaseDecreaseInCustomerDeposits" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInCustomerDeposits" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInCustomerDeposits" use="optional" order="14.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_IncreaseDecreaseInAccruedExpensesAndOtherLiabilities" xlink:label="IncreaseDecreaseInAccruedExpensesAndOtherLiabilities" xlink:title="IncreaseDecreaseInAccruedExpensesAndOtherLiabilities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInAccruedExpensesAndOtherLiabilities" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInAccruedExpensesAndOtherLiabilities" use="optional" order="15.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_IncreaseDecreaseInIncomeTaxAndOtherLiabilitiesNoncurrent" xlink:label="IncreaseDecreaseInIncomeTaxAndOtherLiabilitiesNoncurrent" xlink:title="IncreaseDecreaseInIncomeTaxAndOtherLiabilitiesNoncurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInIncomeTaxAndOtherLiabilitiesNoncurrent" xlink:title="calculation: AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInIncomeTaxAndOtherLiabilitiesNoncurrent" use="optional" order="16.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:label="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:title="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInContinuingOperations" xlink:to="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:title="calculation: NetCashProvidedByUsedInContinuingOperations to NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:title="PaymentsToAcquireBusinessesNetOfCashAcquired" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivitiesContinuingOperations to PaymentsToAcquireBusinessesNetOfCashAcquired" use="optional" order="1.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="PaymentsToAcquirePropertyPlantAndEquipment" xlink:title="PaymentsToAcquirePropertyPlantAndEquipment" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="PaymentsToAcquirePropertyPlantAndEquipment" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivitiesContinuingOperations to PaymentsToAcquirePropertyPlantAndEquipment" use="optional" order="2.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsToAcquireNotesReceivable" xlink:label="PaymentsToAcquireNotesReceivable" xlink:title="PaymentsToAcquireNotesReceivable" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="PaymentsToAcquireNotesReceivable" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivitiesContinuingOperations to PaymentsToAcquireNotesReceivable" use="optional" order="3.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromCollectionOfNotesReceivable" xlink:label="ProceedsFromCollectionOfNotesReceivable" xlink:title="ProceedsFromCollectionOfNotesReceivable" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="ProceedsFromCollectionOfNotesReceivable" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivitiesContinuingOperations to ProceedsFromCollectionOfNotesReceivable" use="optional" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsToAcquireShortTermInvestments" xlink:label="PaymentsToAcquireShortTermInvestments" xlink:title="PaymentsToAcquireShortTermInvestments" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="PaymentsToAcquireShortTermInvestments" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivitiesContinuingOperations to PaymentsToAcquireShortTermInvestments" use="optional" order="5.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromSaleOfShortTermInvestments" xlink:label="ProceedsFromSaleOfShortTermInvestments" xlink:title="ProceedsFromSaleOfShortTermInvestments" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="ProceedsFromSaleOfShortTermInvestments" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivitiesContinuingOperations to ProceedsFromSaleOfShortTermInvestments" use="optional" order="6.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_FundingArrangementToServiceProvider" xlink:label="FundingArrangementToServiceProvider" xlink:title="FundingArrangementToServiceProvider" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:to="FundingArrangementToServiceProvider" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivitiesContinuingOperations to FundingArrangementToServiceProvider" use="optional" order="7.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:label="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:title="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInContinuingOperations" xlink:to="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:title="calculation: NetCashProvidedByUsedInContinuingOperations to NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="ProceedsFromLinesOfCredit" xlink:title="ProceedsFromLinesOfCredit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="ProceedsFromLinesOfCredit" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to ProceedsFromLinesOfCredit" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RepaymentsOfLinesOfCredit" xlink:label="RepaymentsOfLinesOfCredit" xlink:title="RepaymentsOfLinesOfCredit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="RepaymentsOfLinesOfCredit" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to RepaymentsOfLinesOfCredit" use="optional" order="2.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromIssuanceOfDebt" xlink:label="ProceedsFromIssuanceOfDebt" xlink:title="ProceedsFromIssuanceOfDebt" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="ProceedsFromIssuanceOfDebt" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to ProceedsFromIssuanceOfDebt" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromOtherDebt" xlink:label="ProceedsFromOtherDebt" xlink:title="ProceedsFromOtherDebt" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="ProceedsFromOtherDebt" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to ProceedsFromOtherDebt" use="optional" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RepaymentsOfOtherDebt" xlink:label="RepaymentsOfOtherDebt" xlink:title="RepaymentsOfOtherDebt" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="RepaymentsOfOtherDebt" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to RepaymentsOfOtherDebt" use="optional" order="5.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsOfFinancingCosts" xlink:label="PaymentsOfFinancingCosts" xlink:title="PaymentsOfFinancingCosts" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="PaymentsOfFinancingCosts" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to PaymentsOfFinancingCosts" use="optional" order="6.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="ProceedsFromIssuanceOfCommonStock" xlink:title="ProceedsFromIssuanceOfCommonStock" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="ProceedsFromIssuanceOfCommonStock" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to ProceedsFromIssuanceOfCommonStock" use="optional" order="7.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="ProceedsFromStockOptionsExercised" xlink:title="ProceedsFromStockOptionsExercised" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="ProceedsFromStockOptionsExercised" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to ProceedsFromStockOptionsExercised" use="optional" order="8.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsOfDividendsCommonStock" xlink:label="PaymentsOfDividendsCommonStock" xlink:title="PaymentsOfDividendsCommonStock" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="PaymentsOfDividendsCommonStock" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to PaymentsOfDividendsCommonStock" use="optional" order="9.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:label="ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:title="ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" use="optional" order="10.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_PaymentsForRepurchaseOfCommonStockToSatisfyEmployeeTaxWithholdingObligations" xlink:label="PaymentsForRepurchaseOfCommonStockToSatisfyEmployeeTaxWithholdingObligations" xlink:title="PaymentsForRepurchaseOfCommonStockToSatisfyEmployeeTaxWithholdingObligations" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="PaymentsForRepurchaseOfCommonStockToSatisfyEmployeeTaxWithholdingObligations" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to PaymentsForRepurchaseOfCommonStockToSatisfyEmployeeTaxWithholdingObligations" use="optional" order="11.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromMinorityShareholders" xlink:label="ProceedsFromMinorityShareholders" xlink:title="ProceedsFromMinorityShareholders" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="ProceedsFromMinorityShareholders" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to ProceedsFromMinorityShareholders" use="optional" order="12.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsOfDividendsMinorityInterest" xlink:label="PaymentsOfDividendsMinorityInterest" xlink:title="PaymentsOfDividendsMinorityInterest" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="PaymentsOfDividendsMinorityInterest" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to PaymentsOfDividendsMinorityInterest" use="optional" order="13.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_PaymentOfAssumedEmployeeBenefits" xlink:label="PaymentOfAssumedEmployeeBenefits" xlink:title="PaymentOfAssumedEmployeeBenefits" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="PaymentOfAssumedEmployeeBenefits" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivitiesContinuingOperations to PaymentOfAssumedEmployeeBenefits" use="optional" order="14.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations" xlink:label="EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations" xlink:title="EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInContinuingOperations" xlink:to="EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations" xlink:title="calculation: NetCashProvidedByUsedInContinuingOperations to EffectOfExchangeRateOnCashAndCashEquivalentsContinuingOperations" use="optional" order="4.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/BalanceSheet">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_Assets" xlink:label="Assets" xlink:title="Assets" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="AssetsCurrent" xlink:title="AssetsCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="AssetsCurrent" xlink:title="calculation: Assets to AssetsCurrent" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="CashAndCashEquivalentsAtCarryingValue" xlink:title="CashAndCashEquivalentsAtCarryingValue" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="CashAndCashEquivalentsAtCarryingValue" xlink:title="calculation: AssetsCurrent to CashAndCashEquivalentsAtCarryingValue" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="AccountsReceivableNetCurrent" xlink:title="AccountsReceivableNetCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="AccountsReceivableNetCurrent" xlink:title="calculation: AssetsCurrent to AccountsReceivableNetCurrent" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="PrepaidExpenseCurrent" xlink:title="PrepaidExpenseCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="PrepaidExpenseCurrent" xlink:title="calculation: AssetsCurrent to PrepaidExpenseCurrent" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="OtherAssetsCurrent" xlink:title="OtherAssetsCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="OtherAssetsCurrent" xlink:title="calculation: AssetsCurrent to OtherAssetsCurrent" order="5.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InventoryNet" xlink:label="InventoryNet" xlink:title="InventoryNet" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="InventoryNet" xlink:title="calculation: AssetsCurrent to InventoryNet" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="PropertyPlantAndEquipmentNet" xlink:title="calculation: Assets to PropertyPlantAndEquipmentNet" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_Goodwill" xlink:label="Goodwill" xlink:title="Goodwill" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="Goodwill" xlink:title="calculation: Assets to Goodwill" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="IntangibleAssetsNetExcludingGoodwill" xlink:title="IntangibleAssetsNetExcludingGoodwill" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="IntangibleAssetsNetExcludingGoodwill" xlink:title="calculation: Assets to IntangibleAssetsNetExcludingGoodwill" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="OtherAssetsNoncurrent" xlink:title="OtherAssetsNoncurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="OtherAssetsNoncurrent" xlink:title="calculation: Assets to OtherAssetsNoncurrent" order="5.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="LiabilitiesAndStockholdersEquity" xlink:title="LiabilitiesAndStockholdersEquity" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_Liabilities" xlink:label="Liabilities" xlink:title="Liabilities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="Liabilities" xlink:title="calculation: LiabilitiesAndStockholdersEquity to Liabilities" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="LiabilitiesCurrent" xlink:title="LiabilitiesCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="LiabilitiesCurrent" xlink:title="calculation: Liabilities to LiabilitiesCurrent" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtCurrent" xlink:label="DebtCurrent" xlink:title="DebtCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="DebtCurrent" xlink:title="calculation: LiabilitiesCurrent to DebtCurrent" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="AccountsPayableCurrent" xlink:title="AccountsPayableCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="AccountsPayableCurrent" xlink:title="calculation: LiabilitiesCurrent to AccountsPayableCurrent" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CustomerDepositsCurrent" xlink:label="CustomerDepositsCurrent" xlink:title="CustomerDepositsCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="CustomerDepositsCurrent" xlink:title="calculation: LiabilitiesCurrent to CustomerDepositsCurrent" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="AccruedLiabilitiesCurrent" xlink:title="AccruedLiabilitiesCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="AccruedLiabilitiesCurrent" xlink:title="calculation: LiabilitiesCurrent to AccruedLiabilitiesCurrent" use="optional" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="LongTermDebtNoncurrent" xlink:title="LongTermDebtNoncurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="LongTermDebtNoncurrent" xlink:title="calculation: Liabilities to LongTermDebtNoncurrent" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccruedIncomeTaxesNoncurrent" xlink:label="AccruedIncomeTaxesNoncurrent" xlink:title="AccruedIncomeTaxesNoncurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="AccruedIncomeTaxesNoncurrent" xlink:title="calculation: Liabilities to AccruedIncomeTaxesNoncurrent" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_DeferredCompensationLiabilityClassifiedAndOtherLiabilitiesNoncurrent" xlink:label="DeferredCompensationLiabilityClassifiedAndOtherLiabilitiesNoncurrent" xlink:title="DeferredCompensationLiabilityClassifiedAndOtherLiabilitiesNoncurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="DeferredCompensationLiabilityClassifiedAndOtherLiabilitiesNoncurrent" xlink:title="calculation: Liabilities to DeferredCompensationLiabilityClassifiedAndOtherLiabilitiesNoncurrent" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:title="StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:title="calculation: LiabilitiesAndStockholdersEquity to StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="StockholdersEquity" xlink:title="StockholdersEquity" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="StockholdersEquity" xlink:title="calculation: StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest to StockholdersEquity" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="PreferredStockValue" xlink:title="PreferredStockValue" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="PreferredStockValue" xlink:title="calculation: StockholdersEquity to PreferredStockValue" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CommonStockValue" xlink:label="CommonStockValue" xlink:title="CommonStockValue" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="CommonStockValue" xlink:title="calculation: StockholdersEquity to CommonStockValue" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="RetainedEarningsAccumulatedDeficit" xlink:title="RetainedEarningsAccumulatedDeficit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="RetainedEarningsAccumulatedDeficit" xlink:title="calculation: StockholdersEquity to RetainedEarningsAccumulatedDeficit" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:title="AccumulatedOtherComprehensiveIncomeLossNetOfTax" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:title="calculation: StockholdersEquity to AccumulatedOtherComprehensiveIncomeLossNetOfTax" order="5.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="AdditionalPaidInCapitalCommonStock" xlink:title="AdditionalPaidInCapitalCommonStock" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="AdditionalPaidInCapitalCommonStock" xlink:title="calculation: StockholdersEquity to AdditionalPaidInCapitalCommonStock" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_MinorityInterest" xlink:label="MinorityInterest" xlink:title="MinorityInterest" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="MinorityInterest" xlink:title="calculation: StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest to MinorityInterest" order="2.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/StatementOfIncome">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProfitLoss" xlink:label="ProfitLoss" xlink:title="ProfitLoss" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:title="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ProfitLoss" xlink:to="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:title="calculation: ProfitLoss to IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="OperatingIncomeLoss" xlink:title="OperatingIncomeLoss" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:to="OperatingIncomeLoss" xlink:title="calculation: IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments to OperatingIncomeLoss" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_GrossProfit" xlink:label="GrossProfit" xlink:title="GrossProfit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingIncomeLoss" xlink:to="GrossProfit" xlink:title="calculation: OperatingIncomeLoss to GrossProfit" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_Revenues" xlink:label="Revenues" xlink:title="Revenues" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="GrossProfit" xlink:to="Revenues" xlink:title="calculation: GrossProfit to Revenues" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CostOfRevenue" xlink:label="CostOfRevenue" xlink:title="CostOfRevenue" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="GrossProfit" xlink:to="CostOfRevenue" xlink:title="calculation: GrossProfit to CostOfRevenue" use="optional" order="2.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="OperatingExpenses" xlink:title="OperatingExpenses" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingIncomeLoss" xlink:to="OperatingExpenses" xlink:title="calculation: OperatingIncomeLoss to OperatingExpenses" order="2.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LaborAndRelatedExpense" xlink:label="LaborAndRelatedExpense" xlink:title="LaborAndRelatedExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingExpenses" xlink:to="LaborAndRelatedExpense" xlink:title="calculation: OperatingExpenses to LaborAndRelatedExpense" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:label="ProvisionForDoubtfulAccounts" xlink:title="ProvisionForDoubtfulAccounts" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingExpenses" xlink:to="ProvisionForDoubtfulAccounts" xlink:title="calculation: OperatingExpenses to ProvisionForDoubtfulAccounts" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="GeneralAndAdministrativeExpense" xlink:title="GeneralAndAdministrativeExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingExpenses" xlink:to="GeneralAndAdministrativeExpense" xlink:title="calculation: OperatingExpenses to GeneralAndAdministrativeExpense" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="NonoperatingIncomeExpense" xlink:title="NonoperatingIncomeExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:to="NonoperatingIncomeExpense" xlink:title="calculation: IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments to NonoperatingIncomeExpense" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:label="InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:title="InterestIncomeExpenseAndOtherFinancialCostsNet" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NonoperatingIncomeExpense" xlink:to="InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:title="calculation: NonoperatingIncomeExpense to InterestIncomeExpenseAndOtherFinancialCostsNet" use="optional" order="1.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="OtherNonoperatingIncomeExpense" xlink:title="OtherNonoperatingIncomeExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NonoperatingIncomeExpense" xlink:to="OtherNonoperatingIncomeExpense" xlink:title="calculation: NonoperatingIncomeExpense to OtherNonoperatingIncomeExpense" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="IncomeTaxExpenseBenefit" xlink:title="IncomeTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ProfitLoss" xlink:to="IncomeTaxExpenseBenefit" xlink:title="calculation: ProfitLoss to IncomeTaxExpenseBenefit" use="optional" order="2.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:title="NetIncomeLossAvailableToCommonStockholdersBasic" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="ProfitLoss" xlink:title="calculation: NetIncomeLossAvailableToCommonStockholdersBasic to ProfitLoss" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:label="NetIncomeLossAttributableToNoncontrollingInterest" xlink:title="NetIncomeLossAttributableToNoncontrollingInterest" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="NetIncomeLossAttributableToNoncontrollingInterest" xlink:title="calculation: NetIncomeLossAvailableToCommonStockholdersBasic to NetIncomeLossAttributableToNoncontrollingInterest" use="optional" order="2.0" weight="-1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/StatementOfShareholdersEquityAndComprehensiveIncome">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockholdersEquityPeriodIncreaseDecrease" xlink:label="StockholdersEquityPeriodIncreaseDecrease" xlink:title="StockholdersEquityPeriodIncreaseDecrease" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProfitLoss" xlink:label="ProfitLoss" xlink:title="ProfitLoss" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="ProfitLoss" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to ProfitLoss" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:label="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:title="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationGainLossArisingDuringPeriodNetOfTax" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DividendsCash" xlink:label="DividendsCash" xlink:title="DividendsCash" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="DividendsCash" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to DividendsCash" use="optional" order="6.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:title="AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" use="optional" order="8.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:label="StockIssuedDuringPeriodValueShareBasedCompensation" xlink:title="StockIssuedDuringPeriodValueShareBasedCompensation" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="StockIssuedDuringPeriodValueShareBasedCompensation" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to StockIssuedDuringPeriodValueShareBasedCompensation" use="optional" order="9.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueAcquisitions" xlink:label="StockIssuedDuringPeriodValueAcquisitions" xlink:title="StockIssuedDuringPeriodValueAcquisitions" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="StockIssuedDuringPeriodValueAcquisitions" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to StockIssuedDuringPeriodValueAcquisitions" use="optional" order="11.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_ShareRepurchasesRelatedToEmployeeStockBasedCompensationAwardsValue" xlink:label="ShareRepurchasesRelatedToEmployeeStockBasedCompensationAwardsValue" xlink:title="ShareRepurchasesRelatedToEmployeeStockBasedCompensationAwardsValue" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="ShareRepurchasesRelatedToEmployeeStockBasedCompensationAwardsValue" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to ShareRepurchasesRelatedToEmployeeStockBasedCompensationAwardsValue" use="optional" order="12.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="StockIssuedDuringPeriodValueNewIssues" xlink:title="StockIssuedDuringPeriodValueNewIssues" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="StockIssuedDuringPeriodValueNewIssues" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to StockIssuedDuringPeriodValueNewIssues" order="10.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:label="MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:title="MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" use="optional" order="7.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:title="OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockholdersEquityOther" xlink:label="StockholdersEquityOther" xlink:title="StockholdersEquityOther" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="StockholdersEquityOther" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to StockholdersEquityOther" order="13.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_InitialNoncontrollingInterestUponConsolidationOfJointVenture" xlink:label="InitialNoncontrollingInterestUponConsolidationOfJointVenture" xlink:title="InitialNoncontrollingInterestUponConsolidationOfJointVenture" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="InitialNoncontrollingInterestUponConsolidationOfJointVenture" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to InitialNoncontrollingInterestUponConsolidationOfJointVenture" use="optional" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_MinorityInterestIncreaseFromStockIssuance" xlink:label="MinorityInterestIncreaseFromStockIssuance" xlink:title="MinorityInterestIncreaseFromStockIssuance" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="MinorityInterestIncreaseFromStockIssuance" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to MinorityInterestIncreaseFromStockIssuance" use="optional" order="5.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:label="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:title="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:label="StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:title="StockIssuedDuringPeriodSharesShareBasedCompensation" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:to="StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:title="calculation: StockIssuedDuringPeriodSharesPeriodIncreaseDecrease to StockIssuedDuringPeriodSharesShareBasedCompensation" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:label="StockIssuedDuringPeriodSharesAcquisitions" xlink:title="StockIssuedDuringPeriodSharesAcquisitions" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:to="StockIssuedDuringPeriodSharesAcquisitions" xlink:title="calculation: StockIssuedDuringPeriodSharesPeriodIncreaseDecrease to StockIssuedDuringPeriodSharesAcquisitions" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_ShareRepurchasesRelatedToEmployeeStockBasedCompensationAwardsShares" xlink:label="ShareRepurchasesRelatedToEmployeeStockBasedCompensationAwardsShares" xlink:title="ShareRepurchasesRelatedToEmployeeStockBasedCompensationAwardsShares" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:to="ShareRepurchasesRelatedToEmployeeStockBasedCompensationAwardsShares" xlink:title="calculation: StockIssuedDuringPeriodSharesPeriodIncreaseDecrease to ShareRepurchasesRelatedToEmployeeStockBasedCompensationAwardsShares" use="optional" order="4.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="StockIssuedDuringPeriodSharesNewIssues" xlink:title="StockIssuedDuringPeriodSharesNewIssues" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:to="StockIssuedDuringPeriodSharesNewIssues" xlink:title="calculation: StockIssuedDuringPeriodSharesPeriodIncreaseDecrease to StockIssuedDuringPeriodSharesNewIssues" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockholdersEquityOtherShares" xlink:label="StockholdersEquityOtherShares" xlink:title="StockholdersEquityOtherShares" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:to="StockholdersEquityOtherShares" xlink:title="calculation: StockIssuedDuringPeriodSharesPeriodIncreaseDecrease to StockholdersEquityOtherShares" order="5.0" weight="-1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureDebtDetails2">
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:label="InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:title="InterestIncomeExpenseAndOtherFinancialCostsNet" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InvestmentIncomeInterest" xlink:label="InvestmentIncomeInterest" xlink:title="InvestmentIncomeInterest" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:to="InvestmentIncomeInterest" xlink:title="calculation: InterestIncomeExpenseAndOtherFinancialCostsNet to InvestmentIncomeInterest" use="optional" order="1.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_InterestExpenseAndOtherFinancialCostsNet" xlink:label="InterestExpenseAndOtherFinancialCostsNet" xlink:title="InterestExpenseAndOtherFinancialCostsNet" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InterestIncomeExpenseAndOtherFinancialCostsNet" xlink:to="InterestExpenseAndOtherFinancialCostsNet" xlink:title="calculation: InterestIncomeExpenseAndOtherFinancialCostsNet to InterestExpenseAndOtherFinancialCostsNet" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtAndCapitalLeaseObligations" xlink:label="DebtAndCapitalLeaseObligations" xlink:title="DebtAndCapitalLeaseObligations" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:label="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:title="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DebtAndCapitalLeaseObligations" xlink:to="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:title="calculation: DebtAndCapitalLeaseObligations to DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:title="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearTwo" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DebtAndCapitalLeaseObligations" xlink:to="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:title="calculation: DebtAndCapitalLeaseObligations to DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearTwo" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearThree" xlink:title="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearThree" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DebtAndCapitalLeaseObligations" xlink:to="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearThree" xlink:title="calculation: DebtAndCapitalLeaseObligations to DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearThree" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearFour" xlink:label="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearFour" xlink:title="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearFour" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DebtAndCapitalLeaseObligations" xlink:to="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearFour" xlink:title="calculation: DebtAndCapitalLeaseObligations to DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearFour" use="optional" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearFive" xlink:label="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearFive" xlink:title="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearFive" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DebtAndCapitalLeaseObligations" xlink:to="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearFive" xlink:title="calculation: DebtAndCapitalLeaseObligations to DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalInYearFive" use="optional" order="5.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:label="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:title="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalAfterYearFive" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DebtAndCapitalLeaseObligations" xlink:to="DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:title="calculation: DebtAndCapitalLeaseObligations to DebtAndCapitalLeaseObligationsMaturitiesRepaymentsOfPrincipalAfterYearFive" use="optional" order="6.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureCommitmentsAndContingenciesDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:label="OperatingLeasesFutureMinimumPaymentsDue" xlink:title="OperatingLeasesFutureMinimumPaymentsDue" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:label="OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:title="OperatingLeasesFutureMinimumPaymentsDueCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueCurrent" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:label="OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:title="OperatingLeasesFutureMinimumPaymentsDueInTwoYears" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueInTwoYears" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:label="OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:title="OperatingLeasesFutureMinimumPaymentsDueInThreeYears" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueInThreeYears" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:label="OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:title="OperatingLeasesFutureMinimumPaymentsDueInFourYears" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueInFourYears" use="optional" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:label="OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:title="OperatingLeasesFutureMinimumPaymentsDueInFiveYears" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueInFiveYears" use="optional" order="5.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:label="OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:title="OperatingLeasesFutureMinimumPaymentsDueThereafter" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueThereafter" use="optional" order="6.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureIncomeTaxesDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:title="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:label="IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:title="IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:to="IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" xlink:title="calculation: IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments to IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:label="IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:title="IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:to="IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" xlink:title="calculation: IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments to IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="IncomeTaxExpenseBenefit" xlink:title="IncomeTaxExpenseBenefit" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:label="CurrentIncomeTaxExpenseBenefit" xlink:title="CurrentIncomeTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="CurrentIncomeTaxExpenseBenefit" xlink:title="calculation: IncomeTaxExpenseBenefit to CurrentIncomeTaxExpenseBenefit" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CurrentFederalTaxExpenseBenefit" xlink:label="CurrentFederalTaxExpenseBenefit" xlink:title="CurrentFederalTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CurrentIncomeTaxExpenseBenefit" xlink:to="CurrentFederalTaxExpenseBenefit" xlink:title="calculation: CurrentIncomeTaxExpenseBenefit to CurrentFederalTaxExpenseBenefit" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:label="CurrentStateAndLocalTaxExpenseBenefit" xlink:title="CurrentStateAndLocalTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CurrentIncomeTaxExpenseBenefit" xlink:to="CurrentStateAndLocalTaxExpenseBenefit" xlink:title="calculation: CurrentIncomeTaxExpenseBenefit to CurrentStateAndLocalTaxExpenseBenefit" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CurrentForeignTaxExpenseBenefit" xlink:label="CurrentForeignTaxExpenseBenefit" xlink:title="CurrentForeignTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CurrentIncomeTaxExpenseBenefit" xlink:to="CurrentForeignTaxExpenseBenefit" xlink:title="calculation: CurrentIncomeTaxExpenseBenefit to CurrentForeignTaxExpenseBenefit" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="DeferredIncomeTaxExpenseBenefit" xlink:title="DeferredIncomeTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="DeferredIncomeTaxExpenseBenefit" xlink:title="calculation: IncomeTaxExpenseBenefit to DeferredIncomeTaxExpenseBenefit" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:label="DeferredFederalIncomeTaxExpenseBenefit" xlink:title="DeferredFederalIncomeTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredIncomeTaxExpenseBenefit" xlink:to="DeferredFederalIncomeTaxExpenseBenefit" xlink:title="calculation: DeferredIncomeTaxExpenseBenefit to DeferredFederalIncomeTaxExpenseBenefit" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:label="DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:title="DeferredStateAndLocalIncomeTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredIncomeTaxExpenseBenefit" xlink:to="DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:title="calculation: DeferredIncomeTaxExpenseBenefit to DeferredStateAndLocalIncomeTaxExpenseBenefit" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:label="DeferredForeignIncomeTaxExpenseBenefit" xlink:title="DeferredForeignIncomeTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredIncomeTaxExpenseBenefit" xlink:to="DeferredForeignIncomeTaxExpenseBenefit" xlink:title="calculation: DeferredIncomeTaxExpenseBenefit to DeferredForeignIncomeTaxExpenseBenefit" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_NoncurrentIncomeTaxExpenseBenefit" xlink:label="NoncurrentIncomeTaxExpenseBenefit" xlink:title="NoncurrentIncomeTaxExpenseBenefit" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="NoncurrentIncomeTaxExpenseBenefit" xlink:title="calculation: IncomeTaxExpenseBenefit to NoncurrentIncomeTaxExpenseBenefit" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="EffectiveIncomeTaxRateContinuingOperations" xlink:title="EffectiveIncomeTaxRateContinuingOperations" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:label="EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:title="EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="EffectiveIncomeTaxRateContinuingOperations" xlink:to="EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:title="calculation: EffectiveIncomeTaxRateContinuingOperations to EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential" xlink:label="EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential" xlink:title="EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="EffectiveIncomeTaxRateContinuingOperations" xlink:to="EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential" xlink:title="calculation: EffectiveIncomeTaxRateContinuingOperations to EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:label="EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:title="EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="EffectiveIncomeTaxRateContinuingOperations" xlink:to="EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:title="calculation: EffectiveIncomeTaxRateContinuingOperations to EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:label="EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:title="EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="EffectiveIncomeTaxRateContinuingOperations" xlink:to="EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" xlink:title="calculation: EffectiveIncomeTaxRateContinuingOperations to EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther" use="optional" order="4.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureIncomeTaxesDetails2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsNet" xlink:label="DeferredTaxAssetsNet" xlink:title="DeferredTaxAssetsNet" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsGross" xlink:label="DeferredTaxAssetsGross" xlink:title="DeferredTaxAssetsGross" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsNet" xlink:to="DeferredTaxAssetsGross" xlink:title="calculation: DeferredTaxAssetsNet to DeferredTaxAssetsGross" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts" xlink:label="DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts" xlink:title="DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:label="DeferredTaxAssetsOperatingLossCarryforwards" xlink:title="DeferredTaxAssetsOperatingLossCarryforwards" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxAssetsOperatingLossCarryforwards" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxAssetsOperatingLossCarryforwards" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:label="DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:title="DeferredTaxLiabilitiesPropertyPlantAndEquipment" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxLiabilitiesPropertyPlantAndEquipment" use="optional" order="3.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxLiabilitiesGoodwillAndIntangibleAssets" xlink:label="DeferredTaxLiabilitiesGoodwillAndIntangibleAssets" xlink:title="DeferredTaxLiabilitiesGoodwillAndIntangibleAssets" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxLiabilitiesGoodwillAndIntangibleAssets" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxLiabilitiesGoodwillAndIntangibleAssets" use="optional" order="4.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation" xlink:label="DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation" xlink:title="DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation" use="optional" order="5.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities" xlink:label="DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities" xlink:title="DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities" use="optional" order="6.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_DeferredTaxLiabilitiesPrepaidExpense" xlink:label="DeferredTaxLiabilitiesPrepaidExpense" xlink:title="DeferredTaxLiabilitiesPrepaidExpense" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxLiabilitiesPrepaidExpense" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxLiabilitiesPrepaidExpense" use="optional" order="7.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_DeferredTaxLiabilitiesUnrealizedDerivativeGains" xlink:label="DeferredTaxLiabilitiesUnrealizedDerivativeGains" xlink:title="DeferredTaxLiabilitiesUnrealizedDerivativeGains" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxLiabilitiesUnrealizedDerivativeGains" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxLiabilitiesUnrealizedDerivativeGains" use="optional" order="8.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_DeferredTaxAssetsCustomerDeposits" xlink:label="DeferredTaxAssetsCustomerDeposits" xlink:title="DeferredTaxAssetsCustomerDeposits" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxAssetsCustomerDeposits" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxAssetsCustomerDeposits" use="optional" order="9.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxLiabilitiesUnrealizedCurrencyTransactionGains" xlink:label="DeferredTaxLiabilitiesUnrealizedCurrencyTransactionGains" xlink:title="DeferredTaxLiabilitiesUnrealizedCurrencyTransactionGains" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxLiabilitiesUnrealizedCurrencyTransactionGains" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxLiabilitiesUnrealizedCurrencyTransactionGains" use="optional" order="10.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxLiabilitiesOther" xlink:label="DeferredTaxLiabilitiesOther" xlink:title="DeferredTaxLiabilitiesOther" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxLiabilitiesOther" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxLiabilitiesOther" use="optional" order="11.0" weight="-1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureNatureOfBusinessAcquisitionsSignificantAccountingPoliciesAndRecentAccountingPronouncementsDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" xlink:label="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" xlink:title="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationCurrentAssetsCashAndCashEquivalents" xlink:label="BusinessAcquisitionPurchasePriceAllocationCurrentAssetsCashAndCashEquivalents" xlink:title="BusinessAcquisitionPurchasePriceAllocationCurrentAssetsCashAndCashEquivalents" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" xlink:to="BusinessAcquisitionPurchasePriceAllocationCurrentAssetsCashAndCashEquivalents" xlink:title="calculation: BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet to BusinessAcquisitionPurchasePriceAllocationCurrentAssetsCashAndCashEquivalents" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationCurrentAssetsReceivables" xlink:label="BusinessAcquisitionPurchasePriceAllocationCurrentAssetsReceivables" xlink:title="BusinessAcquisitionPurchasePriceAllocationCurrentAssetsReceivables" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" xlink:to="BusinessAcquisitionPurchasePriceAllocationCurrentAssetsReceivables" xlink:title="calculation: BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet to BusinessAcquisitionPurchasePriceAllocationCurrentAssetsReceivables" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationCurrentAssetsInventory" xlink:label="BusinessAcquisitionPurchasePriceAllocationCurrentAssetsInventory" xlink:title="BusinessAcquisitionPurchasePriceAllocationCurrentAssetsInventory" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" xlink:to="BusinessAcquisitionPurchasePriceAllocationCurrentAssetsInventory" xlink:title="calculation: BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet to BusinessAcquisitionPurchasePriceAllocationCurrentAssetsInventory" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationPropertyPlantAndEquipment" xlink:label="BusinessAcquisitionPurchasePriceAllocationPropertyPlantAndEquipment" xlink:title="BusinessAcquisitionPurchasePriceAllocationPropertyPlantAndEquipment" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" xlink:to="BusinessAcquisitionPurchasePriceAllocationPropertyPlantAndEquipment" xlink:title="calculation: BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet to BusinessAcquisitionPurchasePriceAllocationPropertyPlantAndEquipment" use="optional" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationAmortizableIntangibleAssets" xlink:label="BusinessAcquisitionPurchasePriceAllocationAmortizableIntangibleAssets" xlink:title="BusinessAcquisitionPurchasePriceAllocationAmortizableIntangibleAssets" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" xlink:to="BusinessAcquisitionPurchasePriceAllocationAmortizableIntangibleAssets" xlink:title="calculation: BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet to BusinessAcquisitionPurchasePriceAllocationAmortizableIntangibleAssets" use="optional" order="5.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillAmount" xlink:label="BusinessAcquisitionPurchasePriceAllocationGoodwillAmount" xlink:title="BusinessAcquisitionPurchasePriceAllocationGoodwillAmount" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" xlink:to="BusinessAcquisitionPurchasePriceAllocationGoodwillAmount" xlink:title="calculation: BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet to BusinessAcquisitionPurchasePriceAllocationGoodwillAmount" use="optional" order="6.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_BusinessAcquisitionPurchasePriceAllocationOtherCurrentAndNoncurrentAssets" xlink:label="BusinessAcquisitionPurchasePriceAllocationOtherCurrentAndNoncurrentAssets" xlink:title="BusinessAcquisitionPurchasePriceAllocationOtherCurrentAndNoncurrentAssets" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" xlink:to="BusinessAcquisitionPurchasePriceAllocationOtherCurrentAndNoncurrentAssets" xlink:title="calculation: BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet to BusinessAcquisitionPurchasePriceAllocationOtherCurrentAndNoncurrentAssets" use="optional" order="7.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccountsPayable" xlink:label="BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccountsPayable" xlink:title="BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccountsPayable" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" xlink:to="BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccountsPayable" xlink:title="calculation: BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet to BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccountsPayable" use="optional" order="8.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesOtherLiabilities" xlink:label="BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesOtherLiabilities" xlink:title="BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesOtherLiabilities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" xlink:to="BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesOtherLiabilities" xlink:title="calculation: BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet to BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesOtherLiabilities" use="optional" order="9.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccuredExpenseAndOtherLiabilities" xlink:label="BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccuredExpenseAndOtherLiabilities" xlink:title="BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccuredExpenseAndOtherLiabilities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" xlink:to="BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccuredExpenseAndOtherLiabilities" xlink:title="calculation: BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet to BusinessAcquisitionPurchasePriceAllocationCurrentLiabilitiesAccuredExpenseAndOtherLiabilities" use="optional" order="10.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionPurchasePriceAllocationOtherNoncurrentLiabilities" xlink:label="BusinessAcquisitionPurchasePriceAllocationOtherNoncurrentLiabilities" xlink:title="BusinessAcquisitionPurchasePriceAllocationOtherNoncurrentLiabilities" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet" xlink:to="BusinessAcquisitionPurchasePriceAllocationOtherNoncurrentLiabilities" xlink:title="calculation: BusinessAcquisitionPurchasePriceAllocationAssetsAcquiredLiabilitiesAssumedNet to BusinessAcquisitionPurchasePriceAllocationOtherNoncurrentLiabilities" use="optional" order="11.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" xlink:label="BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" xlink:title="BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityLiabilitiesIncurred" xlink:label="BusinessAcquisitionCostOfAcquiredEntityLiabilitiesIncurred" xlink:title="BusinessAcquisitionCostOfAcquiredEntityLiabilitiesIncurred" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" xlink:to="BusinessAcquisitionCostOfAcquiredEntityLiabilitiesIncurred" xlink:title="calculation: BusinessAcquisitionCostOfAcquiredEntityPurchasePrice to BusinessAcquisitionCostOfAcquiredEntityLiabilitiesIncurred" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuable" xlink:label="BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuable" xlink:title="BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuable" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" xlink:to="BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuable" xlink:title="calculation: BusinessAcquisitionCostOfAcquiredEntityPurchasePrice to BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuable" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_BusinessAcquisitionEstimatedCashConsideration" xlink:label="BusinessAcquisitionEstimatedCashConsideration" xlink:title="BusinessAcquisitionEstimatedCashConsideration" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" xlink:to="BusinessAcquisitionEstimatedCashConsideration" xlink:title="calculation: BusinessAcquisitionCostOfAcquiredEntityPurchasePrice to BusinessAcquisitionEstimatedCashConsideration" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_BusinessAcquisitionCostOfAcquiredEntityAmountDueFromAcquiree" xlink:label="BusinessAcquisitionCostOfAcquiredEntityAmountDueFromAcquiree" xlink:title="BusinessAcquisitionCostOfAcquiredEntityAmountDueFromAcquiree" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionEstimatedCashConsideration" xlink:to="BusinessAcquisitionCostOfAcquiredEntityAmountDueFromAcquiree" xlink:title="calculation: BusinessAcquisitionEstimatedCashConsideration to BusinessAcquisitionCostOfAcquiredEntityAmountDueFromAcquiree" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityCashPaid" xlink:label="BusinessAcquisitionCostOfAcquiredEntityCashPaid" xlink:title="BusinessAcquisitionCostOfAcquiredEntityCashPaid" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionEstimatedCashConsideration" xlink:to="BusinessAcquisitionCostOfAcquiredEntityCashPaid" xlink:title="calculation: BusinessAcquisitionEstimatedCashConsideration to BusinessAcquisitionCostOfAcquiredEntityCashPaid" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_BusinessAcquisitionPromissoryNoteNetOfPurchasePriceAdjustment" xlink:label="BusinessAcquisitionPromissoryNoteNetOfPurchasePriceAdjustment" xlink:title="BusinessAcquisitionPromissoryNoteNetOfPurchasePriceAdjustment" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" xlink:to="BusinessAcquisitionPromissoryNoteNetOfPurchasePriceAdjustment" xlink:title="calculation: BusinessAcquisitionCostOfAcquiredEntityPurchasePrice to BusinessAcquisitionPromissoryNoteNetOfPurchasePriceAdjustment" order="2.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureNatureOfBusinessAcquisitionsSignificantAccountingPoliciesAndRecentAccountingPronouncementsDetails3">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="WeightedAverageNumberOfDilutedSharesOutstanding" xlink:title="WeightedAverageNumberOfDilutedSharesOutstanding" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="WeightedAverageNumberOfSharesOutstandingBasic" xlink:title="WeightedAverageNumberOfSharesOutstandingBasic" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="WeightedAverageNumberOfSharesOutstandingBasic" xlink:title="calculation: WeightedAverageNumberOfDilutedSharesOutstanding to WeightedAverageNumberOfSharesOutstandingBasic" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:label="WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:title="WeightedAverageNumberDilutedSharesOutstandingAdjustment" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="WeightedAverageNumberDilutedSharesOutstandingAdjustment" xlink:title="calculation: WeightedAverageNumberOfDilutedSharesOutstanding to WeightedAverageNumberDilutedSharesOutstandingAdjustment" use="optional" order="2.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosurePropertyAndEquipmentDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="PropertyPlantAndEquipmentGross" xlink:title="PropertyPlantAndEquipmentGross" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="PropertyPlantAndEquipmentNet" xlink:to="PropertyPlantAndEquipmentGross" xlink:title="calculation: PropertyPlantAndEquipmentNet to PropertyPlantAndEquipmentGross" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:title="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="PropertyPlantAndEquipmentNet" xlink:to="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:title="calculation: PropertyPlantAndEquipmentNet to AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" use="optional" order="2.0" weight="-1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureGoodwillAndIdentifiableIntangibleAssetsDetails2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="FiniteLivedIntangibleAssetsNet" xlink:title="FiniteLivedIntangibleAssetsNet" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="FiniteLivedIntangibleAssetsGross" xlink:title="FiniteLivedIntangibleAssetsGross" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsNet" xlink:to="FiniteLivedIntangibleAssetsGross" xlink:title="calculation: FiniteLivedIntangibleAssetsNet to FiniteLivedIntangibleAssetsGross" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:title="FiniteLivedIntangibleAssetsAccumulatedAmortization" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsNet" xlink:to="FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:title="calculation: FiniteLivedIntangibleAssetsNet to FiniteLivedIntangibleAssetsAccumulatedAmortization" use="optional" order="2.0" weight="-1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:label="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:title="FiniteLivedIntangibleAssetsFutureAmortizationExpense" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearOne" xlink:label="FutureAmortizationExpenseYearOne" xlink:title="FutureAmortizationExpenseYearOne" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearOne" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearOne" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearTwo" xlink:label="FutureAmortizationExpenseYearTwo" xlink:title="FutureAmortizationExpenseYearTwo" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearTwo" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearTwo" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearThree" xlink:label="FutureAmortizationExpenseYearThree" xlink:title="FutureAmortizationExpenseYearThree" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearThree" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearThree" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearFour" xlink:label="FutureAmortizationExpenseYearFour" xlink:title="FutureAmortizationExpenseYearFour" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearFour" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearFour" use="optional" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearFive" xlink:label="FutureAmortizationExpenseYearFive" xlink:title="FutureAmortizationExpenseYearFive" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearFive" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearFive" use="optional" order="5.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseAfterYearFive" xlink:label="FutureAmortizationExpenseAfterYearFive" xlink:title="FutureAmortizationExpenseAfterYearFive" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseAfterYearFive" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseAfterYearFive" use="optional" order="6.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureDebtDetails2Calc2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtAndCapitalLeaseObligations" xlink:label="DebtAndCapitalLeaseObligations" xlink:title="DebtAndCapitalLeaseObligations" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtCurrent" xlink:label="DebtCurrent" xlink:title="DebtCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DebtAndCapitalLeaseObligations" xlink:to="DebtCurrent" xlink:title="calculation: DebtAndCapitalLeaseObligations to DebtCurrent" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="LongTermDebtNoncurrent" xlink:title="LongTermDebtNoncurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DebtAndCapitalLeaseObligations" xlink:to="LongTermDebtNoncurrent" xlink:title="calculation: DebtAndCapitalLeaseObligations to LongTermDebtNoncurrent" use="optional" order="2.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureShareholdersEquityDetails5">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearOne" xlink:label="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearOne" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearOne" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:to="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearOne" xlink:title="calculation: EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized to EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearOne" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearTwo" xlink:label="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearTwo" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearTwo" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:to="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearTwo" xlink:title="calculation: EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized to EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearTwo" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearThree" xlink:label="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearThree" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearThree" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:to="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearThree" xlink:title="calculation: EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized to EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearThree" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearFour" xlink:label="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearFour" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearFour" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:to="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearFour" xlink:title="calculation: EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized to EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearFour" use="optional" order="4.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearFive" xlink:label="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearFive" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearFive" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:to="EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearFive" xlink:title="calculation: EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized to EmployeeServiceShareBasedCompensationNonvestedAwardsCompensationCostToBeRecognizedInYearFive" use="optional" order="5.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureCommitmentsAndContingenciesDetails2">
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployees" xlink:label="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployees" xlink:title="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployees" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesCurrent" xlink:label="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesCurrent" xlink:title="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesCurrent" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployees" xlink:to="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesCurrent" xlink:title="calculation: FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployees to FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesCurrent" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesYearTwo" xlink:label="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesYearTwo" xlink:title="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesYearTwo" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployees" xlink:to="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesYearTwo" xlink:title="calculation: FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployees to FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesYearTwo" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="int-20111231.xsd#int_FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesYearThree" xlink:label="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesYearThree" xlink:title="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesYearThree" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployees" xlink:to="FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesYearThree" xlink:title="calculation: FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployees to FutureMinimumCommitmentsUnderAgreementsWithExecutiveOfficersAndKeyEmployeesYearThree" use="optional" order="3.0" weight="1.0" />
  </link:calculationLink>
  <link:calculationLink xlink:type="extended" xlink:role="http://www.wfscorp.com/role/DisclosureNatureOfBusinessAcquisitionsSignificantAccountingPoliciesAndRecentAccountingPronouncementsDetailsCalc2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" xlink:label="BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" xlink:title="BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityLiabilitiesIncurred" xlink:label="BusinessAcquisitionCostOfAcquiredEntityLiabilitiesIncurred" xlink:title="BusinessAcquisitionCostOfAcquiredEntityLiabilitiesIncurred" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" xlink:to="BusinessAcquisitionCostOfAcquiredEntityLiabilitiesIncurred" xlink:title="calculation: BusinessAcquisitionCostOfAcquiredEntityPurchasePrice to BusinessAcquisitionCostOfAcquiredEntityLiabilitiesIncurred" use="optional" order="1.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuable" xlink:label="BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuable" xlink:title="BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuable" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" xlink:to="BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuable" xlink:title="calculation: BusinessAcquisitionCostOfAcquiredEntityPurchasePrice to BusinessAcquisitionCostOfAcquiredEntityEquityInterestsIssuedAndIssuable" use="optional" order="2.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityOtherNoncashConsideration" xlink:label="BusinessAcquisitionCostOfAcquiredEntityOtherNoncashConsideration" xlink:title="BusinessAcquisitionCostOfAcquiredEntityOtherNoncashConsideration" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" xlink:to="BusinessAcquisitionCostOfAcquiredEntityOtherNoncashConsideration" xlink:title="calculation: BusinessAcquisitionCostOfAcquiredEntityPurchasePrice to BusinessAcquisitionCostOfAcquiredEntityOtherNoncashConsideration" use="optional" order="3.0" weight="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_BusinessAcquisitionCostOfAcquiredEntityCashPaid" xlink:label="BusinessAcquisitionCostOfAcquiredEntityCashPaid" xlink:title="BusinessAcquisitionCostOfAcquiredEntityCashPaid" />
    <link:calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="BusinessAcquisitionCostOfAcquiredEntityPurchasePrice" xlink:to="BusinessAcquisitionCostOfAcquiredEntityCashPaid" xlink:title="calculation: BusinessAcquisitionCostOfAcquiredEntityPurchasePrice to BusinessAcquisitionCostOfAcquiredEntityCashPaid" use="optional" order="4.0" weight="1.0" />
  </link:calculationLink>
</link:linkbase>
</XBRL>
