REFERENCES
- Harold Fristoe, “A versatile phonographic preamplifier equalizer”, P.R.E. Trans, on Audio, Au-10 (1962).
- Langford-Smith, F., “Radio designers' handbook” (Iliffe & Sons Ltd., London), 142.
- Towers, T. D., “High input impedance circuits”, Wireless World, 74 (July 1968), 1393.