D. Cutting, D. Karger, J. Pedersen, and J. Tukey. Proceedings of the 15th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, page 318-329. ACM Press, (1992)
K. Beyer, J. Goldstein, R. Ramakrishnan, and U. Shaft. Proceeding of the 7th International Conference on Database Theory, volume 1540 of Lecture Notes in Computer Science, page 217-235. Springer, (1999)
U. Shah, T. Finin, and A. Joshi. Proceedings of the eleventh international conference on Information and knowledge management, page 461-468. ACM Press, (2002)
P. Anick, and S. Vaithyanathan. Proceedings of the 20th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, page 314-323. (1997)