1. Stover, E. R., in High Temperature Materials, edit. by Ault, G. M., et al., 2, 437 (Interscience, 1963).
2. Rappeneau, J., et al., presented at Sixth Carbon Conf., Pittsburgh (1963).
3. Oxley, J. H., et al., Amer. Inst. Chem. Eng. J., 7 (3), 498 (1961).
4. Klug, H. P., and Alexander, L. E., X-ray Diffraction Procedures for Polycrystalline and Amorphous Materials (John Wiley and Sons, New York, 1954).
5. Bacon, G. E., J. App. Chem., 6, 477 (1956).