About: http://webisa.webdatacommons.org/80765124

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 solution looks technically fine, except for the worry of handling composite keys - normally doubling the indexing requirements for each table (which can lead to a performance hit).
http://www.w3.org/ns/prov#wasQuotedFrom	ittoolbox.com