1. A. Yu. Ishlinskii, Pravda, May 22, 1976.
2. A. A. Griffith, Philos. Trans. R. Soc., London, Ser. A,221, 163 (1920).
3. G. V. Karpenko, Zavod. Lab.,26, 1134 (1960).
4. M. P. Markovets, Zavod. Lab.,26, 1129 (1960).
5. Zavod. Lab.,26, 319–331; 1104–1140 (1960).