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