@article{JETPL.104.501, title = {}, author = {Tkachenko, V. A. and Tkachenko, O. A. and Minkov, G. M. and Sherstobitov, A. A.}, journal = {JETP Lett.}, volume = {104}, issue = {7}, pages = {473}, year = {2016}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X16190061}, note = {[Pisma v ZhETF 104, 501 (2016)]} }