1. Lord Rayleigh, Proc. Lond. Math. Soc. 17, 4 (1887);
2. Theory of Sound (Dover, New York, 1945).
3. H. Kolsky, Stress Waves in Solids (Dover, New York, 1963).
4. P. M. Morse, Vibrations and Sound (McGraw-Hill, New York, 1948).
5. A. E. H. Love, Some Problems in Geodynamics (Cambridge U. Press, Cambridge, 1911).