1. Gears: Spur, Helical, Bevel, Internal, Epicyclic and Worm;Houghton,1970
2. Design of parallel axes straight spur and helical gear — Choices of materials and preliminary estimation of major dimensions, item No 680-N;ESDU,1972
3. Design of parallel axes straight spur and helical gear — Geometric Design, item No. 77002;ESDU,1972
4. Building Expert Systems in Prolog;Rowe,1989