@article{JETPL.107.23, title = {}, author = {, and Gryaznov, V. K. and Philippov, A. V.}, journal = {JETP Lett.}, volume = {107}, issue = {1}, pages = {19}, year = {2018}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X18010058}, note = {[Pisma v ZhETF 107, 23 (2018)]} }