@article{JETPL.109.89, title = {}, author = {, and Tikhonov, E. S. and Khrapai, V. S.}, journal = {JETP Lett.}, volume = {109}, issue = {2}, pages = {92}, year = {2019}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.1134/S0370274X19020048}, note = {[Pisma v ZhETF 109, 89 (2019)]} }