https://w3id.org/framester/wn/wn30/instances/word-required_course <https://w3id.org/framester/wn/wn30/schema/Word> <https://w3id.org/framester/wn/wn30/schema/lexicalForm> required course rdf:type <https://w3id.org/framester/wn/wn30/schema/Word> risorse dalla linked data cloud