@prefix dct: . @prefix ns1: . @prefix ns2: . @prefix ns3: . @prefix rdfs: . @prefix skos: . a skos:Concept ; dct:created "2019-01-14" ; dct:modified "2019-01-14" ; ns2:hasProfile ; ns1:status ; rdfs:seeAlso ; skos:definition "A period is an interval of time"@en ; skos:exactMatch ; skos:prefLabel "sea surface swell wave mean period"@en ; ns3:hadPrimarySource .