Mila Dalla Preda Completeness Refinement in Abstract Symbolic Trajectory Evaluation. 38-52 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3148&spage=38 2004 conf/sas/2004 SAS db/conf/sas/sas2004.html#Preda04