@inproceedings{ijcai1981p53,
  title     = {Cancellation in a Parallel Semantic Network},
  author    = {Fahlman, Scott E. and Touretzky, David S. and van Roggen, Walter},
  booktitle = {Proceedings of the Seventh International Joint Conference on
               Artificial Intelligence, {IJCAI-81}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {Roger C. Schank},
  pages     = {257--262},
  year      = {1981},
  month     = {8},
  note      = {Nowledge Representation},
  url       = {https://ijcai.org/proceedings/1981/53},
}