@inproceedings{ramshaw-1991-three, title = "A Three-Level Model for Plan Exploration", author = "Ramshaw, Lance A.", booktitle = "29th Annual Meeting of the Association for Computational Linguistics", month = jun, year = "1991", address = "Berkeley, California, USA", publisher = "Association for Computational Linguistics", url = "https://preview.aclanthology.org/ingest_wac_2008/P91-1006/", doi = "10.3115/981344.981350", pages = "39--46" }