1. Klawitten, J. J., thesis, Clemson University, South Carolina (1970).
2. Hulbert, S. F., Klawitten, J. J., Sauer, B. W., and Matthews, J. R., Tech. Rept. No. 2, ONR, N00014-71-A-0339-001 (Proj. No. NR032-529), May 1, 1972.
3. Weber, J. N., White, E. W., and Lebiedzik, J., Nature, 233, 337 (1971).
4. White, R. L., Weber, J. N., and White, E. W., Science, N.Y., 176, 922 (1972).
5. Roy, R., and Tuttle, O. F., Physics and Chemistry of the Earth, 1, 138 (Pergamon, London, 1956).