@prefix rdfs: . @prefix ns1: . @prefix dc: . ns1:author_id rdfs:subPropertyOf dc:identifier . @prefix vcard2006: . ns1:author_id rdfs:subPropertyOf vcard2006:UID . @prefix dct: . ns1:author_id rdfs:subPropertyOf dct:identifier . @prefix bibo: . ns1:author_id rdfs:subPropertyOf bibo:identifier . @prefix sioc: . ns1:author_id rdfs:subPropertyOf sioc:id .