@article{JETPL.105.535, title = {}, author = {Pekh, P. L. and Ratnikov, P. V. and , }, journal = {JETP Lett.}, volume = {105}, issue = {9}, pages = {568}, year = {2017}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X1709003X}, note = {[Pisma v ZhETF 105, 535 (2017)]} }