J. Fan, Y. Gao, H. Luo, and G. Xu. Proceedings of the 27th annual international ACM SIGIR conference
on Research and development in information retrieval, Sheffield,
United Kingdom, page 361 - 368. ACM Press, New York, NY, USA, (2004)
B. Zhu, J. Yan, Q. Li, C. Yang, J. Liu, N. Xu, M. Yi, and K. Cai. CCS '10: Proceedings of the 17th ACM conference on Computer and communications security, page 187--200. New York, NY, USA, ACM, (October 2010)