PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • The US chemical industry has regained competitiveness in recent years as hydraulic fracturing fueled a surge in unconventional oil and gas production, including Marcellus, which has some of the most attractive economics.
http://www.w3.org/ns/prov#wasQuotedFrom
  • chemweek.com