@article{GebserGharibMerceretal.2009,
  author    = {Martin Gebser and Mona Gharib and Robert E. Mercer and Torsten H. Schaub},
  title     = {Monotonic answer set programming},
  doi       = {10.1093/logcom/exn040},
  url       = {http://logcom.oxfordjournals.org/},
  year      = {2009},
}