1. E. Jahnke, F. Emde, Tables of Functions with Formulae and Curves, 4th edn. (Dover, New York, 1945)
2. M. Abramowitz, I.A. Stegun, Handbook of Mathematical Functions with Formulas, Graphs and Mathematical Tables (National Bureau Standards – Applied Mathematics Series #55, Washington, DC, 1964)
3. M. Greenspan, Simple derivation of the Boltzmann-Ehrenfest Adiabatic Principle. J. Acoust. Soc. Am. 27(1), 34–35 (1955)
4. E.C. Wente, A condenser transmitter as a uniformly sensitive instrument for the absolute measurement of sound intensity. Phys. Rev. 10, 39–63 (1917)
5. H.L.F. Helmholtz, On the Sensation of Tone as a Physiological Basis for the Theory of Music (Longmans & Co., London, 1885), ISBN 048660753-4. Reprinted Dover, 1954; See Ch. III – Analysis of musical tones by sympathetic resonance