@article{JETPL.97.654, title = {}, author = {Novikov, V. A. and , }, journal = {JETP Lett.}, volume = {97}, issue = {10}, pages = {568}, year = {2013}, doi = {}, url = {http://jetpletters.ru/ps/0/article_30292.shtml}, note = {[Pisma v ZhETF 97, 654 (2013)]} }