@inproceedings{ijcai1973p21,
  title     = {A Hole in Goal Trees: Some Guidance from Resolution Theory},
  author    = {Loveland, Donald W. and Stickel, Mark E.},
  booktitle = {Proceedings of the Third International Joint Conference on
               Artificial Intelligence, {IJCAI-73}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {Nils J. Nilsson},
  pages     = {153--160},
  year      = {1973},
  month     = {8},
  note      = {Theorem Proving and Logic: 2},
  url       = {https://ijcai.org/proceedings/1973/21},
}