About: http://webisa.webdatacommons.org/283941574

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	The rigid base may be constructed of such materials as prepared ground, wood, concrete, stone, or the like.
http://www.w3.org/ns/prov#wasQuotedFrom	freepatentsonline.com