1. Japanese File Index classification and F-terms
2. Sources of Japanese patent information
3. [3] Japanese Patent Office. www.jpo.go.jp/ Retrieved from the World Wide Web on March 22, 2007
4. [4] www.ryutu.ncipi.go.jp/chart/tokumapf.htm Retrieved from the World Wide Web on March 22, 2007.
5. [5] Industrial Property Digital Library. www.ipdl.ncipi.go.jp/homepg_e.ipdl Retrieved from the World Wide Web on March 22, 2007