About: http://webisa.webdatacommons.org/314274783

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	During the first half of this century, as new analytical techniques were developed, traces of other gases such as carbon monoxide, hydrogen, methane, and ozone were detected.
http://www.w3.org/ns/prov#wasQuotedFrom	ucar.edu