@article{JETPL.109.753, title = {}, author = {Koplak, O. V. and , and , and , and , }, journal = {JETP Lett.}, volume = {109}, issue = {11}, pages = {722}, year = {2019}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.1134/S0370274X19110079}, note = {[Pisma v ZhETF 109, 753 (2019)]} }