Emmanuel Zarpas Simple Yet Efficient Improvements of SAT Based Bounded Model Checking. 174-185 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3312&spage=174 2004 conf/fmcad/2004 FMCAD db/conf/fmcad/fmcad2004.html#Zarpas04