@inproceedings{johnson:2002:ACL,
  author    = {Johnson, Mark},
  title     = {A Simple Pattern-matching Algorithm for Recovering Empty Nodes and their Antecedents},
  booktitle = {Proceedings of the 40th Annual Meeting of the Association for Computational Linguistics (ACL)},
  year      = 2002,
  pages     = {136--143}
}