References
- Bomberger, D. C., “A continuously variable equalizing pre-amplifier”, Audio Eng., April 1949.
- Langford, Smith, Radio Designer's Handbook, 1953, pp. 701–70 (contains descriptions of various such circuits).
- Fling, W. D., “A continuously variable equalizer”, Audio Eng., March 1951.
- Tuttle, W. N., “Bridged T and parallel T null circuits for measurements”, Proc. I.R.E., January 1940.
- Cowles, L. G., “The parallel T resistance-capacitance network”, Proc. I.R.E., December 1952.