P. Bouquet, B. Magnini, L. Serafini, and S. Zanobini. IV International and Interdisciplinary Conference on Modeling and Using Context (CONTEXT'2003), Stanford University (CA, USA), (June 2003)
D. Randell, Z. Cui, and A. Cohn. KR'92. Principles of Knowledge Representation and Reasoning: Proceedings of the Third International Conference, Morgan Kaufmann, San Mateo, California, (1992)