@article{DBLP:journals/tplp/GebserKS11,
  author = {Gebser, Martin and Kaminski, Roland and Schaub, Torsten},
  title = {Complex optimization in answer set programming},
  journal = {{TPLP}},
  volume = {11},
  number = {4-5},
  pages = {821--839},
  year = {2011}
}