About: http://webisa.webdatacommons.org/28186041

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	I think this satisfies all the requirements, except for elegance and speed:
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com