1. Spence, R. W., Sci. Technol, No. 43 59 (1965).
2. Wagner, P., and Dauelsberg, L. B., Carbon 5 271 (1967).
3. Wagner, P., and Dauelsberg, L. B., Carbon 6 373 (1968).
4. Wagner, P., Brit. J. Appl. Phys., 2 293 (1969).
5. Gaol, P. S., Thermal Expansion of Solids Symposium, Sept. 18–20. 1968 (Gaithersburg, MD).