@inproceedings{BroersenVanDerTorreECAI2008,
  author    = {Jan Broersen and
               Leendert van der Torre},
  title     = {Conditional Norms and Dyadic Obligations in Time},
  booktitle = {ECAI 2008 - 18th European Conference on Artificial Intelligence,
               Patras, Greece, July 21-25, 2008, Proceedings},
  series    = {Frontiers in Artificial Intelligence and Applications},
  volume    = {178},
  publisher = {IOS Press},
  year      = {2008},
  pages     = {883-884},
  editor    = {Malik Ghallab and
               Constantine D. Spyropoulos and
               Nikos Fakotakis and
               Nikolaos M. Avouris}
}