@article{JETPL.97.732, title = {}, author = {, and , and Popov, Z. I. and Fedorov, A. S. and , and , and , }, journal = {JETP Lett.}, volume = {97}, issue = {11}, pages = {634}, year = {2013}, doi = {}, url = {http://jetpletters.ru/ps/0/article_30316.shtml}, note = {[Pisma v ZhETF 97, 732 (2013)]} }