@inproceedings{ijcai1993p86,
  title     = {On the Hardness of Approximate Reasoning},
  author    = {Roth, Dan},
  booktitle = {Proceedings of the Thirteenth International Joint Conference on
               Artificial Intelligence, {IJCAI-93}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {Ruzena Bajcsy},
  pages     = {613--618},
  year      = {1993},
  note      = {Knowledge Representation},
  url       = {https://ijcai.org/proceedings/1993/86},
}