@techreport{prologsystem,
  author	= {Pereira, L. and Pereira, F. and Warren, D.},
  month		= sep,
  year		= {1978},
  title		= {Users Guide to DECsystem-10 PROLOG},
  number	= {03/13/5570},
  address	= {Lisbon},
  institution	= {Laboratorio Nacional De Engenharia Civil}
}