Copyright (©) 2019 N. T. Kartel, L. V. Ivanov, A. N. Lyapunov, O. A. Nardid, Ya. O. Cherkashina, E. V. Shcherbak, O. A. Gurova, A. V. Okotrub

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.