@article{JETPL.94.234, title = {}, author = {Silkin, I. V. and , and , and , and Chulkov, E. V.}, journal = {JETP Lett.}, volume = {94}, issue = {3}, pages = {217}, year = {2011}, doi = {}, url = {http://jetpletters.ru/ps/0/article_29477.shtml}, note = {[Pisma v ZhETF 94, 234 (2011)]} }