S. Bao, G. Xue, X. Wu, Y. Yu, B. Fei, and Z. Su. WWW '07: Proceedings of the 16th international conference on World Wide Web, page 501--510. New York, NY, USA, ACM Press, (2007)
L. Page, S. Brin, R. Motwani, and T. Winograd. Proceedings of the 7th International World Wide Web Conference, page 161--172. Brisbane, Australia, (1998)
A. Hotho, R. Jäschke, C. Schmitz, and G. Stumme. Proceedings of the 3rd European Semantic Web Conference, volume 4011 of LNCS, page 411-426. Budva, Montenegro, Springer, (June 2006)