Head-Driven Generation with HPSG Graham Wilcock author 1998-08 text 36th Annual Meeting of the Association for Computational Linguistics and 17th International Conference on Computational Linguistics, Volume 2 Association for Computational Linguistics Montreal, Quebec, Canada conference publication wilcock-1998-head 10.3115/980691.980796 https://aclanthology.org/P98-2227/ 1998-08 1393 1397