@prefix rdf: . @prefix skos: . @prefix rdfs: . @prefix api: . @prefix foaf: . skos:broader . skos:broader . a skos:Concept , rdfs:Resource ; skos:broader ; skos:narrower , , , , , ; skos:prefLabel "Optical telescopes"@en . skos:broader . skos:broader . skos:broader . skos:broader . skos:narrower . a api:ItemEndpoint , api:Page ; api:definition ; api:extendedMetadataVersion ; foaf:primaryTopic .