<xs:element name="Thesaurus" type="ThesaurusCoreStructure"> <xs:unique name="ThesaurusConceptIdentifier"> <xs:selector xpath="bs8723:ThesaurusConcept"/>
<xs:field xpath="@dc:identifier"/>
</xs:unique> <xs:unique name="ThesaurusTermIdentifier"> <xs:selector xpath="bs8723:ThesaurusConcept/bs8723:PreferredTerm|bs8723:ThesaurusConcept/bs8723:NonPreferredTerm"/>
<xs:field xpath="@dc:identifier"/>
</xs:unique> <xs:keyref name="ThesaurusConceptBroader" refer="ThesaurusConceptIdentifier"> <xs:selector xpath="bs8723:ThesaurusConcept/bs8723:HasBroaderConcept"/>
<xs:field xpath="."/>
</xs:keyref> <xs:keyref name="ThesaurusConceptNarrower" refer="ThesaurusConceptIdentifier"> <xs:selector xpath="bs8723:ThesaurusConcept/bs8723:HasNarrowerConcept"/>
<xs:field xpath="."/>
</xs:keyref> <xs:keyref name="ThesaurusConceptRelated" refer="ThesaurusConceptIdentifier"> <xs:selector xpath="bs8723:ThesaurusConcept"/>
<xs:field xpath="bs8723:HasRelatedConcept"/>
</xs:keyref> </xs:element>