@article{journals/fuin/GottlobT96,
  title = "Approximating the Stable Model Semantics is Hard",
  author = "Georg Gottlob and Miroslaw Truszczynski",
  year = "1996",
  journal = "Fundam. Inform.",
  number = "1-2",
  pages = "123-128",
  volume = "28",
}