Janusz Szuba Agnieszka Ozimek Andy Schürr On Graphs in Conceptual Engineering Design. 75-89 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3062&spage=75 2003 conf/agtive/2003 AGTIVE db/conf/agtive/agtive2003.html#SzubaOS03