1. and 1983. ‘GOSSYM: a simulator of cotton crop growth and yield,’ South Carolina Agricultural Experiment Station, Technical Bulletin, No. 1089.
2. 1987. WHAM: A Wheat Modelling Expert System (User manual), Technical Report 1/87, Department of Computer Science, University of Melbourne, Australia.
3. Borland International. 1988. Turbo Prolog: Owner's Handbook, Borland, Scotts Valley, California.
4. and 1984. Programming in Prolog, Springer-Verlag, Berlin.