@inproceedings{ijcai1991p50,
  title     = {Where the Really Hard Problems Are},
  author    = {Cheeseman, Peter C. and Kanefsky, Bob and Taylor, William M.},
  booktitle = {Proceedings of the Twelfth International Joint Conference on
               Artificial Intelligence, {IJCAI-91}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {John Mylopoulos and Ray Reiter},
  pages     = {331--339},
  year      = {1991},
  month     = {8},
  note      = {Automated Reasoning},
  url       = {https://ijcai.org/proceedings/1991/50},
}