PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • There are good explanations of such tools as Wordtracker, Google Suggest, Overture Keyword Suggestion and Google Keyword Sandbox, aswell as a whole list of lesser known but powerful research tools.
http://www.w3.org/ns/prov#wasQuotedFrom
  • threadwatch.org