Dennis Dams Kedar S. Namjoshi Automata as Abstractions. 216-232 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3385&spage=216 2005 conf/vmcai/2005 VMCAI db/conf/vmcai/vmcai2005.html#DamsN05