@article{BCGM92ic,
  author = {R. Barbuti and M. Codish and R. Giacobazzi and M. Maher},
  title="Oracle {S}emantics for {P}{R}{O}{L}{O}{G}",
  journal = {Information and Computation},
  volume =  {122},
  number = {2},
  pages = {178-200},
  year = {1995}}