1. A prolog extension for handling negative knowledge;Aida;New Generation Computing,1983
2. PROLOG: a language for implementing expert systems;Clark,1982
3. Development of the PROSPECTOR consultation system for mineral exploration;Duda,1978
4. Knowledge and the functions of the user interface;Edmonds;IEE Digest,1984
5. A Prolog shell for logic based expert systems;Hammond,1983