@article{JETPL.110.376, title = {}, author = {Volkov, M. K. and Pivovarov, A. A.}, journal = {JETP Lett.}, volume = {110}, issue = {6}, pages = {394}, year = {2019}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.1134/S0370274X19180048}, note = {[Pisma v ZhETF 110, 376 (2019)]} }