PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • In optical communication systems, messages are transmitted by carrier waves at optical frequencies that are generated by such sources as lasers and light-emitting diodes.
http://www.w3.org/ns/prov#wasQuotedFrom
  • google.com