@inproceedings{ijcai1999p4,
  title     = {Complexity Results for Propositional Closed World Reasoning and Circumscription from Tractable Knowledge Bases},
  author    = {Coste-Marquis, Sylvie and Marquis, Pierre},
  booktitle = {Proceedings of the Sixteenth International Joint Conference on
               Artificial Intelligence, {IJCAI-99}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {Thomas Dean},
  year      = {1999},
  url       = {https://ijcai.org/proceedings/1999/4},
}