@article{JETPL.95.72, title = {}, author = {Shein, I. R. and , }, journal = {JETP Lett.}, volume = {95}, issue = {2}, pages = {}, year = {2012}, doi = {}, url = {http://jetpletters.ru/ps/0/article_29621.shtml}, note = {[Pisma v ZhETF 95, 72 (2012)]} }