C. Basu, H. Hirsh, and W. Cohen. Proceedings of the 15th National Conference on
Artificial Intelligence (AAAI-98) and of the 10th
Conference on Innovative Applications of Artificial
Intelligence (IAAI-98), page 714--720. Menlo Park, AAAI Press, (1998)
S. Banerjee, and T. Pedersen. CICLing '02: Proceedings of the Third International Conference on Computational Linguistics and Intelligent Text Processing, page 136--145. London, UK, Springer-Verlag, (2002)
W. Hersh, C. Buckley, T. Leone, and and D. H. Hickam. Proceedings of the 17th Annual International ACM SIGIR Conference on Research and Development in Informaion Retrieval, ACM Press, (1994)