Enrico Giunchiglia Fausto Giunchiglia Armando Tacchella The SAT-Based Approach for Classical Modal Logics. 95-106 http://link.springer.de/link/service/series/0558/bibs/1792/17920095.htm 1999 conf/aiia/1999 AI*IA db/conf/aiia/aiia1999.html#GiunchigliaGT99