@article{DelgrandeSchaubTompits2006,
  author    = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans},
  title     = {A Preference-Based Framework for Updating logic Programs : preliminary reports},
  year      = {2006},
  language  = {en}
}
@article{DelgrandeSchaubTompits2006,
  author    = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans},
  title     = {An Extended Query language for action languages (and its application to aggregates and preferences)},
  year      = {2006},
  language  = {en}
}