About: http://webisa.webdatacommons.org/133022228

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	However, since high purity is not required, it is usually economical to use an oxygen containing gas such as air.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com