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    <link:label id="lab_ck0001027596_WhenIssuedSecuritiesRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_WhenIssuedSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">When-Issued Securities Risk Member</link:label>
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    <link:label id="lab_ck0001027596_S000041568Member_documentation_en-US" xlink:label="lab_ck0001027596_S000041568Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Medalist Partners MBS Total Return Fund , S000041568</link:label>
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    <link:label id="lab_ck0001027596_C000129090Member_documentation_en-US" xlink:label="lab_ck0001027596_C000129090Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">MEDALIST PARTNERS MBS TOTAL RETURN FUND, C000129090, SEMPX</link:label>
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    <link:label id="lab_ck0001027596_CollateralizedLoanObligationRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_CollateralizedLoanObligationRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Collateralized Loan Obligation Risk Member</link:label>
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    <link:label id="lab_ck0001027596_RepurchaseAgreementRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_RepurchaseAgreementRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Repurchase Agreement Risk Member</link:label>
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    <link:label id="lab_ck0001027596_FixedIncomeSecuritiesRiskInterestRateRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_FixedIncomeSecuritiesRiskInterestRateRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fixed Income Securities Risk, Interest Rate Risk Member</link:label>
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    <link:label id="lab_ck0001027596_FixedIncomeSecuritiesRiskPrepaymentRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_FixedIncomeSecuritiesRiskPrepaymentRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fixed Income Securities Risk, Prepayment Risk Member</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_FixedIncomeSecuritiesRiskPrepaymentRiskMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_FixedIncomeSecuritiesRiskPrepaymentRiskMember"/>
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    <link:label id="lab_ck0001027596_PrivatelyIssuedMortgageRelatedSecuritiesRiskMember_label_en-US" xlink:label="lab_ck0001027596_PrivatelyIssuedMortgageRelatedSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Privately Issued Mortgage-Related Securities Risk Member</link:label>
    <link:label id="lab_ck0001027596_PrivatelyIssuedMortgageRelatedSecuritiesRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_PrivatelyIssuedMortgageRelatedSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Privately Issued Mortgage-Related Securities Risk Member</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_PrivatelyIssuedMortgageRelatedSecuritiesRiskMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_PrivatelyIssuedMortgageRelatedSecuritiesRiskMember"/>
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    <link:label id="lab_ck0001027596_C000164429Member_documentation_en-US" xlink:label="lab_ck0001027596_C000164429Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">MEDALIST PARTNERS MBS TOTAL RETURN FUND Class, C000164429, SEMOX</link:label>
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    <link:label id="lab_ck0001027596_RisksAssociatedWithMortgageBackedAndOtherAssetBackedSecuritiesRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_RisksAssociatedWithMortgageBackedAndOtherAssetBackedSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Risks Associated With Mortgage-Backed And Other Asset-Backed Securities Risk Member</link:label>
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    <link:label id="lab_ck0001027596_Bloomberg1-3YearUSTreasuryIndexreflectsnodeductionforfeesexpensesortaxesIndexMember_documentation_en-US" xlink:label="lab_ck0001027596_Bloomberg1-3YearUSTreasuryIndexreflectsnodeductionforfeesexpensesortaxesIndexMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Bloomberg 1-3 Year U.S. Treasury Index (reflects no deduction for fees, expenses or taxes)</link:label>
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    <link:label id="lab_ck0001027596_HighYieldRiskMember_label_en-US" xlink:label="lab_ck0001027596_HighYieldRiskMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">High Yield Risk Member</link:label>
    <link:label id="lab_ck0001027596_HighYieldRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_HighYieldRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">High Yield Risk Member</link:label>
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    <link:label id="lab_ck0001027596_FixedIncomeSecuritiesRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_FixedIncomeSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fixed-Income Securities Risk Member</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_FixedIncomeSecuritiesRiskMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_FixedIncomeSecuritiesRiskMember"/>
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    <link:label id="lab_ck0001027596_RisksAssociatedWithRealEstateAndRegulatoryActionsMember_documentation_en-US" xlink:label="lab_ck0001027596_RisksAssociatedWithRealEstateAndRegulatoryActionsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Risks Associated With Real Estate And Regulatory Actions Member</link:label>
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    <link:label id="lab_ck0001027596_InvestmentCompanyRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_InvestmentCompanyRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Investment Company Risk Member</link:label>
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    <link:label id="lab_ck0001027596_EconomicAndMarketRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_EconomicAndMarketRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Economic And Market Risk Member</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_EconomicAndMarketRiskMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_EconomicAndMarketRiskMember"/>
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    <link:label id="lab_ck0001027596_ConcentrationRiskMember_label_en-US" xlink:label="lab_ck0001027596_ConcentrationRiskMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Concentration Risk Member</link:label>
    <link:label id="lab_ck0001027596_ConcentrationRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_ConcentrationRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Concentration Risk Member</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_ConcentrationRiskMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_ConcentrationRiskMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001027596_ConcentrationRiskMember" xlink:to="lab_ck0001027596_ConcentrationRiskMember" xlink:type="arc" order="1"/>
    <link:label id="lab_ck0001027596_S000044807Member_label_en-US" xlink:label="lab_ck0001027596_S000044807Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Medalist Partners Short Duration Fund</link:label>
    <link:label id="lab_ck0001027596_S000044807Member_documentation_en-US" xlink:label="lab_ck0001027596_S000044807Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Medalist Partners Short Duration Fund, S000044807</link:label>
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    <link:label id="lab_ck0001027596_C000139162Member_documentation_en-US" xlink:label="lab_ck0001027596_C000139162Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Medalist Partners Short Duration Fund, C000139162, SEMIX</link:label>
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    <link:label id="lab_ck0001027596_Bloomberg1-3YearGovernmentIndexreflectsnodeductionforfeesexpensesortaxesIndexMember_label_en-US" xlink:label="lab_ck0001027596_Bloomberg1-3YearGovernmentIndexreflectsnodeductionforfeesexpensesortaxesIndexMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Bloomberg 1-3 Year Government Index (reflects no deduction for fees, expenses or taxes)</link:label>
    <link:label id="lab_ck0001027596_Bloomberg1-3YearGovernmentIndexreflectsnodeductionforfeesexpensesortaxesIndexMember_documentation_en-US" xlink:label="lab_ck0001027596_Bloomberg1-3YearGovernmentIndexreflectsnodeductionforfeesexpensesortaxesIndexMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Bloomberg 1-3 Year Government Index (reflects no deduction for fees, expenses or taxes)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_Bloomberg1-3YearGovernmentIndexreflectsnodeductionforfeesexpensesortaxesIndexMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_Bloomberg1-3YearGovernmentIndexreflectsnodeductionforfeesexpensesortaxesIndexMember"/>
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    <link:label id="lab_ck0001027596_ManagementRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_ManagementRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Management Risk Member</link:label>
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    <link:label id="lab_ck0001027596_Rule144ASecuritiesRiskMember_label_en-US" xlink:label="lab_ck0001027596_Rule144ASecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Rule 144A Securities Risk Member</link:label>
    <link:label id="lab_ck0001027596_Rule144ASecuritiesRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_Rule144ASecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Rule 144A Securities Risk Member</link:label>
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    <link:label id="lab_ck0001027596_ResidentialMortgageBackedSecuritiesRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_ResidentialMortgageBackedSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Residential Mortgage-Backed Securities Risk Member</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_ResidentialMortgageBackedSecuritiesRiskMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_ResidentialMortgageBackedSecuritiesRiskMember"/>
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    <link:label id="lab_ck0001027596_MunicipalSecuritiesRiskMember_label_en-US" xlink:label="lab_ck0001027596_MunicipalSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Municipal Securities Risk Member</link:label>
    <link:label id="lab_ck0001027596_MunicipalSecuritiesRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_MunicipalSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Municipal Securities Risk Member</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_MunicipalSecuritiesRiskMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_MunicipalSecuritiesRiskMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001027596_MunicipalSecuritiesRiskMember" xlink:to="lab_ck0001027596_MunicipalSecuritiesRiskMember" xlink:type="arc" order="1"/>
    <link:label id="lab_ck0001027596_CreditRiskTransferSecuritiesRiskMember_label_en-US" xlink:label="lab_ck0001027596_CreditRiskTransferSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Credit Risk Transfer Securities Risk Member</link:label>
    <link:label id="lab_ck0001027596_CreditRiskTransferSecuritiesRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_CreditRiskTransferSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Credit Risk Transfer Securities Risk Member</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_CreditRiskTransferSecuritiesRiskMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_CreditRiskTransferSecuritiesRiskMember"/>
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    <link:label id="lab_ck0001027596_LiquidityRiskMember_label_en-US" xlink:label="lab_ck0001027596_LiquidityRiskMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Liquidity Risk Member</link:label>
    <link:label id="lab_ck0001027596_LiquidityRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_LiquidityRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Liquidity Risk Member</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_LiquidityRiskMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_LiquidityRiskMember"/>
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    <link:label id="lab_ck0001027596_C000139163Member_label_en-US" xlink:label="lab_ck0001027596_C000139163Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Medalist Partners Short Duration Fund Investor Class</link:label>
    <link:label id="lab_ck0001027596_C000139163Member_documentation_en-US" xlink:label="lab_ck0001027596_C000139163Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Medalist Partners Short Duration Fund, C000139163, SEMRX</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_C000139163Member" xlink:href="ck0001027596-20260327.xsd#ck0001027596_C000139163Member"/>
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    <link:label id="lab_ck0001027596_CounterpartyRiskMember_label_en-US" xlink:label="lab_ck0001027596_CounterpartyRiskMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Counterparty Risk Member</link:label>
    <link:label id="lab_ck0001027596_CounterpartyRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_CounterpartyRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Counterparty Risk Member</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_CounterpartyRiskMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_CounterpartyRiskMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001027596_CounterpartyRiskMember" xlink:to="lab_ck0001027596_CounterpartyRiskMember" xlink:type="arc" order="1"/>
    <link:label id="lab_ck0001027596_FixedIncomeSecuritiesRiskExtensionRiskMember_label_en-US" xlink:label="lab_ck0001027596_FixedIncomeSecuritiesRiskExtensionRiskMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Fixed Income Securities Risk, Extension Risk Member</link:label>
    <link:label id="lab_ck0001027596_FixedIncomeSecuritiesRiskExtensionRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_FixedIncomeSecuritiesRiskExtensionRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Fixed Income Securities Risk, Extension Risk Member</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_FixedIncomeSecuritiesRiskExtensionRiskMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_FixedIncomeSecuritiesRiskExtensionRiskMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001027596_FixedIncomeSecuritiesRiskExtensionRiskMember" xlink:to="lab_ck0001027596_FixedIncomeSecuritiesRiskExtensionRiskMember" xlink:type="arc" order="1"/>
    <link:label id="lab_ck0001027596_BloombergU.S.AggregateBondIndexReflectsNoDeductionForFeesExpensesOrTaxesIndexMember_label_en-US" xlink:label="lab_ck0001027596_BloombergU.S.AggregateBondIndexReflectsNoDeductionForFeesExpensesOrTaxesIndexMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)</link:label>
    <link:label id="lab_ck0001027596_BloombergU.S.AggregateBondIndexReflectsNoDeductionForFeesExpensesOrTaxesIndexMember_documentation_en-US" xlink:label="lab_ck0001027596_BloombergU.S.AggregateBondIndexReflectsNoDeductionForFeesExpensesOrTaxesIndexMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_BloombergU.S.AggregateBondIndexReflectsNoDeductionForFeesExpensesOrTaxesIndexMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_BloombergU.S.AggregateBondIndexReflectsNoDeductionForFeesExpensesOrTaxesIndexMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001027596_BloombergU.S.AggregateBondIndexReflectsNoDeductionForFeesExpensesOrTaxesIndexMember" xlink:to="lab_ck0001027596_BloombergU.S.AggregateBondIndexReflectsNoDeductionForFeesExpensesOrTaxesIndexMember" xlink:type="arc" order="1"/>
    <link:label id="lab_ck0001027596_CommercialMortgageBackedSecuritiesRiskMember_label_en-US" xlink:label="lab_ck0001027596_CommercialMortgageBackedSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Commercial Mortgage-Backed Securities Risk Member</link:label>
    <link:label id="lab_ck0001027596_CommercialMortgageBackedSecuritiesRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_CommercialMortgageBackedSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Commercial Mortgage-Backed Securities Risk Member</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_CommercialMortgageBackedSecuritiesRiskMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_CommercialMortgageBackedSecuritiesRiskMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_ck0001027596_CommercialMortgageBackedSecuritiesRiskMember" xlink:to="lab_ck0001027596_CommercialMortgageBackedSecuritiesRiskMember" xlink:type="arc" order="1"/>
    <link:label id="lab_ck0001027596_C000129089Member_label_en-US" xlink:label="lab_ck0001027596_C000129089Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">Medalist Partners MBS Total Return Fund Institutional Class</link:label>
    <link:label id="lab_ck0001027596_C000129089Member_documentation_en-US" xlink:label="lab_ck0001027596_C000129089Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">Medalist Partners MBS Total Return Fund , C000129089, SEMMX</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_C000129089Member" xlink:href="ck0001027596-20260327.xsd#ck0001027596_C000129089Member"/>
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    <link:label id="lab_ck0001027596_USGovernmentSecuritiesRiskMember_label_en-US" xlink:label="lab_ck0001027596_USGovernmentSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xml:lang="en-US">U.S. Government Securities Risk Member</link:label>
    <link:label id="lab_ck0001027596_USGovernmentSecuritiesRiskMember_documentation_en-US" xlink:label="lab_ck0001027596_USGovernmentSecuritiesRiskMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xml:lang="en-US">U.S. Government Securities Risk Member</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_ck0001027596_USGovernmentSecuritiesRiskMember" xlink:href="ck0001027596-20260327.xsd#ck0001027596_USGovernmentSecuritiesRiskMember"/>
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