1. Borsky, V., and Matyas, M.: Computation by electronic analog Computers, (ILIFFE Books Ltd., London 1968)
2. Korn, G.A., and Korn, T.M.: Electronic analog and hybrid computers, 2nd edn(McGraw-Hill Book Company 1972)
3. Kenjo, T., and Nagamori, S.: Permanent magnet and brushless DC Motors, (Clarendon Press 1985)
4. Astrom, K.J., and Wittenmark, B.: Computer controlled systems: theory and design, (Prentice-Hall Int. Edns 1984)