@inproceedings{danescu-niculescu-mizil-etal-2009-without,
    title = "Without a `doubt'? Unsupervised Discovery of Downward-Entailing Operators",
    author = "Danescu-Niculescu-Mizil, Cristian  and
      Lee, Lillian  and
      Ducott, Richard",
    editor = "Ostendorf, Mari  and
      Collins, Michael  and
      Narayanan, Shri  and
      Oard, Douglas W.  and
      Vanderwende, Lucy",
    booktitle = "Proceedings of Human Language Technologies: The 2009 Annual Conference of the North {A}merican Chapter of the Association for Computational Linguistics",
    month = jun,
    year = "2009",
    address = "Boulder, Colorado",
    publisher = "Association for Computational Linguistics",
    url = "https://preview.aclanthology.org/fix-sig-urls/N09-1016/",
    pages = "137--145"
}