1. Ahrens, T. J. and Rosenberg, J. T.: 1968, in B. M. French and N. M. Short (eds.),Shock Metamorphism of Natural Materials, Mono, Baltimore, maryland.
2. Angenheister, G. and Pohl, J.: 1964,Z. Geophys. 30, 258.
3. Bartel, L. C.: 1969a,J. Appl. Phys. 40, 661.
4. Bartel, L. C.: 1969b,J. Appl. Phys. 40, 3988.
5. Block. D. and Pavlovic, A. S.: 1969, in R. S. Bradley (ed.),Advances in High Pressure Research, Academic Press, London.