@article{JETPL.94.517, title = {}, author = {, and Orlov, A. P.}, journal = {JETP Lett.}, volume = {94}, issue = {6}, pages = {481}, year = {2011}, doi = {}, url = {http://jetpletters.ru/ps/0/article_29532.shtml}, note = {[Pisma v ZhETF 94, 517 (2011)]} }