M. Petrovic, H. Liu, и H. Jacobsen. VLDB '05: Proceedings of the 31st international conference on Very large data bases, стр. 1279-1282. VLDB Endowment, (2005)
K. Sia, .. J, K. Hino, Y. Chi, S. Zhu, и B. Tseng. , in Proceedings of the International Conference on Weblogs and Social Media (Boulder Colorado, March 2007),, стр. 161-168. (2007)