1. Nelson, P.A., Elliott, S.J.: Active Control of Sound. Academic Press, San Diego (1992)
2. Kuo, S.M., Morgan, D.R.: Algorithms and DSP Implementations, Active Noise Control System. Wiley, New York (1996)
3. Nelson, P.A., Curtis, A.R.D., Elliot, S.J., et al.: The minimum power of free field point sources and the active control of sound. Journal of Sound and Vibration 116, 397–414 (1987)
4. Lueg, P.: Process of silencing sound oscillations, U.S. Patent#2,043,416 (1936)
5. Olson, H.F., May, E.G.: Electronic sound absorber. Acoust. Soc. Am. 25, 1130–1136 (1953)