About: http://webisa.webdatacommons.org/341335872

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	In an embodiment, a radiopaque object, such as a metal or other material object, for example a BB, may be placed into holes on a radiolucent marker sheet such that all marker coordinates are known.
http://www.w3.org/ns/prov#wasQuotedFrom	google.es