About: http://webisa.webdatacommons.org/118437588

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	This same site notes that in MySQL, NOT EXISTS is not optimised like other RDBMS and LEFT JOIN is better
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com