1. Wolf, F. P., Progr. Colloid Polym. Sci.64, 195 (1978).
2. Wolf, F. P., Progr. Colloid Polym. Sci.66, 223 (1979).
3. Rayleigh, J. W., The Theory of Sound, § 157 Dover-Publ. (New York 1945).
4. Pochhammer, L., Journal f. d. reine u. angew. Math.81, 324 (1876).
5. Chree, C., Quart. Journ. of Pure and Appl. Math.21, 287 (1886).