Jan Obdrzálek Fast Mu-Calculus Model Checking when Tree-Width Is Bounded. 80-92 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2725&spage=80 2003 conf/cav/2003 CAV db/conf/cav/cav2003.html#Obdrzalek03