About: http://webisa.webdatacommons.org/26920027

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	Direct comparisons, even for large areas such as counties, require a correspondence file, or ???crosswalk,??? between 1990, 2000, and 2010 geographies.
http://www.w3.org/ns/prov#wasQuotedFrom	slideshare.net