Boris Böhlen Specific Graph Models and Their Mappings to a Common Model. 45-60 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3062&spage=45 2003 conf/agtive/2003 AGTIVE db/conf/agtive/agtive2003.html#Bohlen03