@InProceedings{UpdateSemanticsNaic97,
  Title                    = {An Update Semantics for Deontic Reasoning},
  Author                   = {Torre, L.W.N. van der, and Tan, Y.-H.},
  Booktitle                = {Proceedings of the 9th Dutch Conference on Artificial Intelligence (NAICÕ97)},
  Year                     = {1997},

  Url                      = {http://icr.uni.lu/leonvandertorre/papers/naic971.ps.Z}
}