@techreport{EndrissEtAlTR2004,
  author =        {Ulle Endriss and Paolo Mancarella and Fariba Sadri and Giacomo Terreni and Francesca Toni},
  title =         {The CIFF Proof Procedure: Definition and Soundness Results},
  institution =   {Department of Computing, Imperial College London},
  number =        {2004/2},
  month =         {May},
  year =          {2004}
}