1. (Lord Rayleigh), Theory of Sound, 2nd edit., Dover Publications, New York, 1945, Chaps. 4 and 5.
2. (), and , Treatise on Natural Philosophy, Part I, Cambridge University Press, London, 1903, Secs. 339–345.
3. The Stability of Motion, Pergamon Press, London, 1961, Chap. 5.
4. Hydrodynamic and Hydromagnetic Stability, Oxford University Press, Oxford, 1961, Chaps. 10 and 14.
5. Lambda-Matrices and Vibrating Systems, Pergamon Press, London, 1966, Chap. 7.