Julien Hué Odile Papini Eric Würbel Syntactic Propositional Belief Bases Fusion with Removed Sets. 66-77 2007 conf/ecsqaru/2007 ECSQARU http://dx.doi.org/10.1007/978-3-540-75256-1_9 db/conf/ecsqaru/ecsqaru2007.html#HuePW07