1. F.V. Hunt, Electroacoustics (Wiley, New York, 1954)
2. R.J. Urick, Principles of Underwater Sound, 3rd edn. (Peninsula, Los Altos Hills, CA, 1983)
3. R.T. Beyer, Sounds of Our Times (Springer/AIP Press, New York, 1999)
4. J.W.S. Rayleigh, The Theory of Sound, vol. 1 (Dover, New York, 1945), p. 3
5. L.E. Kinsler, A.R. Frey, A.B. Coppens, J.V. Sanders, Fundamentals of Acoustics, 4th edn. (Wiley, New York, 2000), p. 121