X. Wu, L. Zhang, и Y. Yu. WWW '06: Proceedings of the 15th international conference on World Wide Web, стр. 417--426. New York, NY, USA, ACM Press, (2006)
J. Lu, L. Ma, L. Zhang, J. Brunner, C. Wang, Y. Pan, и Y. Yu. VLDB '07: Proceedings of the 33rd international conference on Very large data bases, стр. 1402--1405. VLDB Endowment, (2007)