Itsuki Noda Hitoshi Matsubara Kazuo Hiraki Ian Frank 233-250 1998 12 Applied Artificial Intelligence 2-3 http://taylorandfrancis.metapress.com/openurl.asp?genre=article&issn=0883-9514&volume=12&issue=2&spage=233 db/journals/aai/aai12.html#NodaMHF98