@article{JETPL.107.673, title = {}, author = {Grigoriev, S. V. and Pshenichnyi, K. A. and , and , and , and , and , }, journal = {JETP Lett.}, volume = {107}, issue = {10}, pages = {640}, year = {2018}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X18100107}, note = {[Pisma v ZhETF 107, 673 (2018)]} }