B. Liu, M. Hu, and J. Cheng. WWW '05: Proceedings of the 14th international conference on World Wide Web, page 342--351. New York, NY, USA, ACM, (2005)
G. Fung, J. Yu, P. Yu, and H. Lu. VLDB '05: Proceedings of the 31st international conference on Very large data bases, page 181--192. VLDB Endowment, (2005)
S. Jokela, M. Turpeinen, T. Kurki, E. Savia, and R. Sulonen. HICSS '01: Proceedings of the 34th Annual Hawaii International Conference on System Sciences ( HICSS-34)-Volume 7, page 7044. Washington, DC, USA, IEEE Computer Society, (2001)