T. Joachims. Proceedings of the eighth ACM SIGKDD international conference on Knowledge discovery and data mining, page 133--142. New York, NY, USA, ACM, (2002)
C. Castillo, D. Donato, and A. Gionis. Proceedings of String Processing and Information Retrieval (SPIRE), volume 4726 of LNCS, page 107--117. Santiago, Chile, Springer, (October 2007)
R. Yan, J. Tang, X. Liu, D. Shan, and X. Li. Proceedings of the 20th ACM international conference on Information and knowledge management, page 1247--1252. New York, NY, USA, ACM, (2011)