1. Z. G. Pinsker, X-ray Crystal Optics (Nauka, Moscow, 1982) [in Russian].
2. A. A. Dyshekov, Cryst. Rep. 58, 984 (2013).
3. A. N. Kolmogorov and S. V. Fomin, Elements of the Theory of Functions and Functional Analysis (Nauka, Moscow, 1981) [in Russian].
4. Yu. I. Sirotin and M. P. Shaskol’skaya, Fundamentals of Crystal Physics (Nauka, Moscow, 1975) [in Russian].