1. J. Weber:Theory of the gravitational radiation detector with ferroelectric crystal coupling, inExperimental Gravitation, edited byB. Bertotti (New York, N. Y., 1974).
2. G. Pizzella:Riv. Nuovo Cimento,5, 369 (1975).
3. R. Ruffini andJ. A. Wheeler:Relativistic cosmology and space platforms, inESRO Colloquium, Interlaken, Switzerland, September 1969.
4. H. Lamb:The Dynamical Theory of Sound (New York, N. Y., 1960).
5. L. D. Landau andE. M. Lifschitz:Theory of Elasticity (New York, N. Y., 1959).