@article{JETPL.106.561, title = {}, author = {Tikhonov, A. M.}, journal = {JETP Lett.}, volume = {106}, issue = {9}, pages = {576}, year = {2017}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X17210056}, note = {[Pisma v ZhETF 106, 561 (2017)]} }