@article{JETPL.94.141, title = {}, author = {, and Muravev, V. M. and Andreev, I. V. and Kukushkin, I. V.}, journal = {JETP Lett.}, volume = {94}, issue = {2}, pages = {137}, year = {2011}, doi = {}, url = {http://jetpletters.ru/ps/0/article_29447.shtml}, note = {[Pisma v ZhETF 94, 141 (2011)]} }