G. Xue, C. Lin, Q. Yang, W. Xi, H. Zeng, Y. Yu, and Z. Chen. SIGIR '05: Proceedings of the 28th annual international ACM SIGIR conference on Research and development in information retrieval, page 114--121. New York, NY, USA, ACM Press, (2005)
Z. Huang, X. Li, and H. Chen. JCDL '05: Proceedings of the 5th ACM/IEEE-CS joint conference on Digital libraries, page 141--142. New York, NY, USA, ACM Press, (2005)