Charles L. A. Clarke Gordon V. Cormack Jamie Callan David Hawking Alan F. Smeaton SIGIR 2003: Proceedings of the 26th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, July 28 - August 1, 2003, Toronto, Canada SIGIR ACM 1-58113-646-3 2003 https://doi.org/10.1145/860435 db/conf/sigir/sigir2003.html