1. N. T. Andrianov and E. S. Lukin, Thermal Aging of Ceramics [in Russian], Metallurgiya, Moscow (1979).
2. É. V. Degtyareva, Theoretical and Technological Investigations in the Sphere of Refractories [in Russian], Ukrainian Scientific-Research Institute of Refractories collection of articles, Metallurgiya, Moscow (1968), No. 9, pp. 62?81.
3. S. M. Kapadia and M. H. Leipold, J. Am. Ceram. Soc.,57, No. 1, 41?42 (1974).
4. V. Ishitobi, M. Shimade, M. Koizumi, et al., Ceramurgia Int.,3, No. 3, 123?124 (1977).
5. É. V. Degtyareva, in: Experiment in Technical Mineralogy and Petrography [in Russian], Nauka, Moscow (1966), pp. 212?218.