M. Tatu. ACL 2005, 43rd Annual Meeting of the Association for Computational Linguistics, Proceedings of the Conference, 25-30 June 2005, University of Michigan, USA, The Association for Computational Linguistics, (2005)
M. Hearst. Proceedings of the 14th conference on Computational linguistics-Volume 2, page 539--545. Association for Computational Linguistics Morristown, NJ, USA, (1992)