Chitta Baral Gerhard Brewka John S. Schlipf Logic Programming and Nonmonotonic Reasoning, 9th International Conference, LPNMR 2007, Tempe, AZ, USA, May 15-17, 2007, Proceedings LPNMR Lecture Notes in Computer Science 4483 Springer 2007 978-3-540-72199-4 db/conf/lpnmr/lpnmr2007.html