@article{SchaubBrueningNicolas1996,
  author    = {Schaub, Torsten H. and Br{\"u}ning, Stefan and Nicolas, Pascal},
  title     = {XRay : a prolog technology theorem prover for default reasoning: a system description},
  isbn      = {3-540-61511-3},
  year      = {1996},
  language  = {en}
}