@inproceedings{foret-nir-2002-rigid,
    title = "Rigid {L}ambek Grammars Are Not Learnable from Strings",
    author = "Foret, Annie  and
      Nir, Yannick Le",
    booktitle = "{COLING} 2002: The 19th International Conference on Computational Linguistics",
    year = "2002",
    url = "https://preview.aclanthology.org/fix-sig-urls/C02-1111/"
}