@article{JETPL.107.554, title = {}, author = {, and Snigirev, A. M. and , }, journal = {JETP Lett.}, volume = {107}, issue = {9}, pages = {527}, year = {2018}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X18090023}, note = {[Pisma v ZhETF 107, 554 (2018)]} }