@article{JETPL.98.466, title = {}, author = {Molotkov, S. N.}, journal = {JETP Lett.}, volume = {98}, issue = {7}, pages = {410}, year = {2013}, doi = {}, url = {http://jetpletters.ru/ps/0/article_30453.shtml}, note = {[Pisma v ZhETF 98, 466 (2013)]} }