About: http://webisa.webdatacommons.org/250349511

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	Other indexing means such as gates, fingers or other movable elements extending across the track from below, above or to the side are also contemplated as practical alternatives to pins.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com