@article{JETPL.110.465, title = {}, author = {Davidovich, M. V.}, journal = {JETP Lett.}, volume = {110}, issue = {7}, pages = {472}, year = {2019}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.1134/S0370274X19190068}, note = {[Pisma v ZhETF 110, 465 (2019)]} }