@InProceedings{kamigaito-EtAl:2015:EMNLP,
  author    = {Kamigaito, Hidetaka  and  Watanabe, Taro  and  Takamura, Hiroya  and  Okumura, Manabu  and  Sumita, Eiichiro},
  title     = {Hierarchical Back-off Modeling of Hiero Grammar based on Non-parametric Bayesian Model},
  booktitle = {Proceedings of the 2015 Conference on Empirical Methods in Natural Language Processing},
  month     = {September},
  year      = {2015},
  address   = {Lisbon, Portugal},
  publisher = {Association for Computational Linguistics},
  pages     = {1217--1227},
  url       = {https://aclweb.org/anthology/D/D15/D15-1143}
}