@inproceedings{ijcai1973p55,
  title     = {PAS-II: An Interactive Task-Free Version of an Automatic Protocol Analysis System},
  author    = {Waterman, Donald A. and Newell, Allen},
  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     = {431--444},
  year      = {1973},
  month     = {8},
  note      = {Psychology and A.I},
  url       = {https://ijcai.org/proceedings/1973/55},
}