About: http://webisa.webdatacommons.org/147648614

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	Their history is reconstructed by looking for isotopes, including carbon-14, that cosmic rays generate in the atmosphere.
http://www.w3.org/ns/prov#wasQuotedFrom	washingtonpost.com