@article{JETPL.95.462, title = {}, author = {Shumilin, A. V.}, journal = {JETP Lett.}, volume = {95}, issue = {8}, pages = {416}, year = {2012}, doi = {}, url = {http://jetpletters.ru/ps/0/article_29685.shtml}, note = {[Pisma v ZhETF 95, 462 (2012)]} }