@article{JETPL.108.14, title = {}, author = {, and Popov, Z. I. and Vysotin, M. A. and Kvashnin, D. G. and Sorokin, P. B.}, journal = {JETP Lett.}, volume = {108}, issue = {1}, pages = {13}, year = {2018}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.1134/S0370274X18130039}, note = {[Pisma v ZhETF 108, 14 (2018)]} }