About: http://webisa.webdatacommons.org/420173801

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	@Andrew Yes, it is what I meant and I think your answer is the best solution, except it replaces even single spaces with single spaces (which is not needed).
http://www.w3.org/ns/prov#wasQuotedFrom	stackoverflow.com