@article{JETPL.107.595, title = {}, author = {Prudnikov, V. V. and Prudnikov, P. V. and , and , }, journal = {JETP Lett.}, volume = {107}, issue = {9}, pages = {569}, year = {2018}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X18090102}, note = {[Pisma v ZhETF 107, 595 (2018)]} }