@article{journals/ai/EiterG92,
  title = "On the Complexity of Propositional Knowledge Base Revision, Updates, and Counterfactuals",
  author = "Thomas Eiter and Georg Gottlob",
  year = "1992",
  journal = "Artif. Intell.",
  number = "2-3",
  pages = "227-270",
  volume = "57",
}