P. Heymann, G. Koutrika, and H. Garcia-Molina. WSDM '08: Proceedings of the international conference on Web search and web data mining, page 195--206. New York, NY, USA, ACM, (2008)
Y. Yanbe, A. Jatowt, S. Nakamura, and K. Tanaka. JCDL '07: Proceedings of the 7th ACM/IEEE-CS joint conference on Digital libraries, page 107--116. New York, NY, USA, ACM, (2007)
B. Krause, A. Hotho, and G. Stumme. Advances in Information Retrieval, 30th European Conference on IR Research, ECIR 2008, 4956, page 101-113. Springer, (2008)