Y. Liu, B. Gao, T. Liu, Y. Zhang, Z. Ma, S. He, and H. Li. Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval, page 451--458. New York, NY, USA, ACM, (2008)
D. Cai, Z. Shao, X. He, X. Yan, and J. Han. LinkKDD '05: Proceedings of the 3rd international workshop on Link discovery, page 58--65. New York, NY, USA, ACM, (2005)