@article{JETPL.109.729, title = {}, author = {, and Tikhonova, O. V.}, journal = {JETP Lett.}, volume = {109}, issue = {11}, pages = {695}, year = {2019}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.1134/S0370274X1911002X}, note = {[Pisma v ZhETF 109, 729 (2019)]} }