@inproceedings{hoepelman-van-hoof-1990-conditionals,
    title = "Conditionals and Counterfactuals in {P}rolog",
    author = "Hoepelman, J. Ph.  and
      van Hoof, A.J.M.",
    booktitle = "{COLING} 1990 Volume 3: Papers presented to the 13th International Conference on Computational Linguistics",
    year = "1990",
    url = "https://preview.aclanthology.org/fix-sig-urls/C90-3075/"
}