@article{JETPL.95.583, title = {}, author = {, and , and , }, journal = {JETP Lett.}, volume = {95}, issue = {10}, pages = {515}, year = {2012}, doi = {}, url = {http://jetpletters.ru/ps/0/article_29707.shtml}, note = {[Pisma v ZhETF 95, 583 (2012)]} }