1. N. N. Sheftal’. In:Growth of Crystals, Vol. 1, Consultants Bureau, New York (1959), p. 5.
2. N. N. Sheftal’. In:Growth of Crystals, Vol. 3, Consultants Bureau, New York (1962), p. 3.
3. G. I. Distler. In:Growth of Crystals, Consultants Bureau, New York (1968), p. 51.
4. G. I. Distler and V. V. Zvyagin. Dokl. AN SSSR, 174 (5):1082 (1967).
5. G. I. Distler, S. A. Kobzareva, and V. S. Chudakov. Fiz. Tverd. Tela, 9 (l):p. 269 (1967).