G. Xue, H. Zeng, Z. Chen, W. Ma, H. Zhang, and C. Lu. SIGIR '03: Proceedings of the 26th annual international ACM SIGIR conference on Research and development in informaion retrieval, page 56--63. New York, NY, USA, ACM, (2003)
J. Zhou, C. Ding, and D. Androutsos. CASCON '06: Proceedings of the 2006 conference of the Center for Advanced Studies on Collaborative research, New York, NY, USA, ACM, (2006)
G. Xue, H. Zeng, Z. Chen, W. Ma, H. Zhang, and C. Lu. SIGIR '03: Proceedings of the 26th annual international ACM SIGIR conference on Research and development in informaion retrieval, page 56--63. New York, NY, USA, ACM, (2003)
J. Zhou, C. Ding, and D. Androutsos. CASCON '06: Proceedings of the 2006 conference of the Center for Advanced Studies on Collaborative research, New York, NY, USA, ACM, (2006)