About: http://webisa.webdatacommons.org/333342146

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	> Not a good way, no. What you need is a constraint, or a BEFORE trigger, that
http://www.w3.org/ns/prov#wasQuotedFrom	postgresql.org