@InProceedings{mohri-roark:2006:HLT-NAACL06-Main,
  author    = {Mohri, Mehryar  and  Roark, Brian},
  title     = {Probabilistic Context-Free Grammar Induction Based on Structural Zeros},
  booktitle = {Proceedings of the Human Language Technology Conference of the NAACL, Main Conference},
  month     = {June},
  year      = {2006},
  address   = {New York City, USA},
  publisher = {Association for Computational Linguistics},
  pages     = {312--319},
  url       = {http://www.aclweb.org/anthology/N/N06/N06-1040}
}