François Denis Aurélien Lemay Alain Terlutte Residual Finite State Automata. 339-368 2002 51 Fundam. Inform. 4 http://iospress.metapress.com/openurl.asp?genre=article&issn=0169-2968&volume=51&issue=4&spage=339 db/journals/fuin/fuin51.html#DenisLT02