Yoshihiko Kakutani Masahito Hasegawa Parameterizations and Fixed-Point Operators on Control Categories. 153-172 2005 65 Fundam. Inform. 1-2 http://iospress.metapress.com/openurl.asp?genre=article&issn=0169-2968&volume=65&issue=1&spage=153 db/journals/fuin/fuin65.html#KakutaniH05