1. Aubry, J.F., Pfitscher, G.H., El-Hefnawy,A. A., Louis, J.P. (1981). IEEE 1981 IECI Proceedings “Applications of Mini and Microcomputers”, San Francisco, Nov.9–12, 1981, pp 393–398.
2. Bjaresten, N.A. (1963). Direct Current,T.8, n°6, juin 1963,pp 154–165.
3. Bühler, H. (1969). Bulletin Oerlikon,n°392–393,pp 22–30, 1969.
4. Buxbaum, A., Schierau, K. (1976). AEG-Telefunken-Hanbücher Elitera-verlap, Berlin, 1976.