@article{JETPL.105.411, title = {}, author = {, and Kvashnin, D. G. and Kvashnin, A. G. and Sorokin, P. B.}, journal = {JETP Lett.}, volume = {105}, issue = {7}, pages = {419}, year = {2017}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X17070013}, note = {[Pisma v ZhETF 105, 411 (2017)]} }