1. Bobrow, D.G .: If PROLOG is the answer, what is the question? In Proc. of the Int. Conf. on 5th Generation Computer Systems, ICOT 1984, 138–145
2. Bobrow, D.G.; Stefik, M.: The Loops Manual. Xerox Corp., Dec. 1983
3. Feigenbaum, E.A.: The art of artificial intelligence - themes and case studies of knowledge engineering. National Computer Conference 1978, AFIPS-Proceedings, 227–240
4. Sheil, B.: Power Tools for Programmers. Datamation, Febr. 1983, 131–144
5. Shortliffe, E.H.: Computer based medical consultations: MYCIN. North-Holland, Amsterdam 1976