M. Thelen, and E. Riloff. Proceedings of the Conference on Empirical Methods in Natural Language Processing (EMNLP), page 214--221. Philadelphia, PA, USA, ACL, (2002)
E. Gaussier, J. Renders, I. Matveeva, C. Goutte, and H. Déjean. Proceedings of the 42nd Meeting of the Association for Computational Linguistics (ACL'04), Main Volume, page 526--533. Barcelona, Spain, (July 2004)