@article{DBLP:journals/fuin/BesnardS94,
  author = {Besnard, Philippe and Schaub, Torsten},
  title = {Possible Worlds Semantics for Default Logics},
  journal = {Fundam. Inform.},
  volume = {21},
  number = {1/2},
  pages = {39--66},
  year = {1994}
}