@InProceedings{billott-lang:1989:ACL,
  author    = {Sylvie Billott  and  Bernard Lang},
  title     = {The Structure of Shared Forests in Ambiguous Parsing},
  booktitle = {Proceedings of the 27th Annual Meeting of the Association for Computational Linguistics},
  month     = {June},
  year      = {1989},
  address   = {Vancouver, British Columbia, Canada},
  publisher = {Association for Computational Linguistics},
  pages     = {143--151},
  url       = {http://www.aclweb.org/anthology/P89-1018},
  doi       = {10.3115/981623.981641}
}