M. Sanderson, and B. Croft. 22nd Annual Internation ACM SIGIR Conference on Research and Development in Information Retrieval, page 206--213. Berkeley, California, United States, ACM Press, (1999)
M. Sanderson, and W. Croft. Proceedings of the 22nd Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, SIGIR'99, page 206--213. (1999)