@article{JETPL.94.110, title = {}, author = {Menshchikova, T. V. and , and Chulkov, E. V.}, journal = {JETP Lett.}, volume = {94}, issue = {2}, pages = {106}, year = {2011}, doi = {}, url = {http://jetpletters.ru/ps/0/article_29440.shtml}, note = {[Pisma v ZhETF 94, 110 (2011)]} }