P. Kroha. Database and Expert Systems Applications, volume 1873 of Lecture Notes in Computer Science, page 675-684. Springer Berlin / Heidelberg, (2000)
B. Lavoie, O. Rambow, and E. Reiter. Proceedings of the Fifth Conference on Applied Natural Language Processing (ANLP-97), page 253--256. Morristown, NJ, USA, Association for Computational Linguistics, (1997)