@article{JETPL.97.104, title = {}, author = {Sokolov, A. E. and Ovchinnikov, S. G. and , and , and , }, journal = {JETP Lett.}, volume = {97}, issue = {2}, pages = {98}, year = {2013}, doi = {}, url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X13020070}, note = {[Pisma v ZhETF 97, 104 (2013)]} }