W. Xi, B. Zhang, Z. Chen, Y. Lu, S. Yan, W. Ma, and E. Fox. WWW '04: Proceedings of the 13th international conference on World Wide Web, page 319--327. New York, NY, USA, ACM Press, (2004)
A. Agarwal, and S. Chakrabarti. ICML '07: Proceedings of the 24th international conference on Machine learning, page 9--16. New York, NY, USA, ACM Press, (2007)
B. Poblete, C. Castillo, and A. Gionis. CIKM '08: Proceeding of the 17th ACM conference on Information and knowledge mining, page 1123--1132. New York, NY, USA, ACM, (2008)
J. Hopcroft, and D. Sheldon. Algorithms and Models for the Web-Graph (WAW), volume 2863 of Lecture Notes in Computer Science, page 68--81. Springer, (December 2007)