Preference Grammars: Softening Syntactic Constraints to Improve Statistical Machine Translation Ashish Venugopal author Andreas Zollmann author Noah A Smith author Stephan Vogel author 2009-06 text Proceedings of Human Language Technologies: The 2009 Annual Conference of the North American Chapter of the Association for Computational Linguistics Mari Ostendorf editor Michael Collins editor Shri Narayanan editor Douglas W Oard editor Lucy Vanderwende editor Association for Computational Linguistics Boulder, Colorado conference publication venugopal-etal-2009-preference https://aclanthology.org/N09-1027/ 2009-06 236 244