K. Aberer, P. Cudré-Mauroux, and M. Hauswirth. Proceedings of the 12th International Conference on World Wide Web (WWW'03), page 197--206. New York, NY, USA, ACM Press, (May 2003)
Y. Kalfoglou, and W. Schorlemmer. Semantic Interoperability and Integration, volume 04391 of Dagstuhl Seminar Proceedings, IBFI, Schloss Dagstuhl, Germany, (2005)