About: http://webisa.webdatacommons.org/188259187

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	Your answer is a good one too, but it has a drawback, since it relies on having Mathematica, which is not cheap.
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com