@article{JETPL.109.301, title = {}, author = {Kudryashov, S. I. and , and Ageev, E. I. and , }, journal = {JETP Lett.}, volume = {109}, issue = {5}, pages = {298}, year = {2019}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.1134/S0370274X19050047}, note = {[Pisma v ZhETF 109, 301 (2019)]} }