@article{FaberKonczak2005,
  author    = {Faber, Wolfgang and Konczak, Kathrin},
  title     = {Strong Equivalence for Logic Programs with Preferences},
  year      = {2005},
  language  = {en}
}
@article{BrainFaberMarateaetal.2007,
  author    = {Brain, Martin and Faber, Wolfgang and Maratea, Marco and Polleres, Axel and Schaub, Torsten H. and Schindlauer, Roman},
  title     = {What should an ASP solver output? : a multiple position paper},
  year      = {2007},
  language  = {en}
}