R. Li, S. Bao, Y. Yu, B. Fei, and Z. Su. WWW '07: Proceedings of the 16th international conference on World Wide Web, page 943--952. New York, NY, USA, ACM Press, (2007)
P. Mika. International Semantic Web Conference, volume 3729 of Lecture Notes in Computer Science, page 522--536. International Semantic Web Conference 2005, Springer, (November 2005)