I. Horrocks, U. Sattler, and S. Tobies. Proceedings of the 6th International Conference on Logic for Programming and Automated Reasoning (LPAR'99), 1705, page 161--180. Springer-Verlag, (1999)
E. Oren, J. Breslin, and S. Decker. WWW '06: Proceedings of the 15th international conference on World Wide Web, page 1071--1072. New York, NY, USA, ACM Press, (2006)
S. Auer, S. Dietzold, and T. Riechert. Proceedings of 5th International Semantic Web Conference, Nov 5th-9th, Athens, GA, USA, LNCS 4273, Berlin Heidelberg, Springer-Verlag, (2006)