Reinhard Pichler, Stefan Rümmele, Stefan Szeider, Stefan Woltran. Tractable Answer-Set Programming with Weight Constraints: Bounded Treewidth Is not Enough. Principles of Knowledge Representation and Reasoning: Proceedings of the Twelfth International Conference, KR 2010, Toronto, Ontario, Canada, May 9-13, 2010 (Fangzhen Lin, Ulrike Sattler, Miroslaw Truszczynski, eds.), 2010, AAAI Press.