About: http://webisa.webdatacommons.org/254930470

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	U.S. Pat. No. 4,274,081 --Nomura et al discloses a data input apparatus including a keyboard and a plurality of interchangeable mats which define the function of the keyboard keys.
http://www.w3.org/ns/prov#wasQuotedFrom	google.es