Christian Bauckhage Franz Kummert Gerhard Sagerer A Structural Framework for Assembly Modeling and Recognition. 49-56 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2756&spage=49 2003 conf/caip/2003 CAIP db/conf/caip/caip2003.html#BauckhageKS03