S. Heymans, T. Eiter, und G. Xiao. Proc. of 19th European Conference on Artificial Intelligence (ECAI), Volume 215 von Frontiers in Artificial Intelligence and Applications, Seite 35--40. IOS Press, (2010)
M. Ortiz, S. Rudolph, und M. Simkus. Principles of Knowledge Representation and Reasoning: Proceedings of the Twelfth International Conference (KR-10), Seite 269-279. AAAI Press, (Mai 2010)