@conference {IIIA-2007-1286, title = {On the Logic of Normative systems}, booktitle = {Twentieth International Joint Conference on AI, IJCAI07}, year = {2007}, pages = {1175-1180}, publisher = {AAAI Press}, organization = {AAAI Press}, author = {Thomas Agotnes and Wiebe van der Hoek and Juan A. Rodr{\'\i}guez-Aguilar and Carles Sierra and Michael Wooldridge} }