@inproceedings{hegner-1991-horn,
    title = "{H}orn Extended Feature Structures: Fast Unification With Negation and Limited Disjunction",
    author = "Hegner, Stephen J.",
    editor = {Kunze, J{\"u}rgen  and
      Reimann, Dorothee},
    booktitle = "Fifth Conference of the {E}uropean Chapter of the Association for Computational Linguistics",
    month = apr,
    year = "1991",
    address = "Berlin, Germany",
    publisher = "Association for Computational Linguistics",
    url = "https://aclanthology.org/E91-1007/"
}