@InProceedings{johnson:1990:ACL,
  author    = {Johnson, Mark},
  title     = {EXPRESSING DISJUNCTIVE AND NEGATIVE FEATURE CONSTRAINTS WITH CLASSICAL FIRST-ORDER LOGIC.},
  booktitle = {Proceedings of the 28th Annual Meeting of the Association for Computational Linguistics},
  month     = {June},
  year      = {1990},
  address   = {Pittsburgh, Pennsylvania, USA},
  publisher = {Association for Computational Linguistics},
  pages     = {173--179},
  url       = {http://www.aclweb.org/anthology/P90-1022},
  doi       = {10.3115/981823.981845}
}