@InProceedings{venugopal-EtAl:2009:NAACLHLT09,
  author    = {Venugopal, Ashish  and  Zollmann, Andreas  and  Smith, Noah A.  and  Vogel, Stephan},
  title     = {Preference Grammars: Softening Syntactic Constraints to Improve Statistical Machine Translation},
  booktitle = {Proceedings of Human Language Technologies: The 2009 Annual Conference of the North American Chapter of the Association for Computational Linguistics},
  month     = {June},
  year      = {2009},
  address   = {Boulder, Colorado},
  publisher = {Association for Computational Linguistics},
  pages     = {236--244},
  url       = {http://www.aclweb.org/anthology/N/N09/N09-1027}
}