@article{JETPL.95.689, title = {}, author = {Rosanov, N. N.}, journal = {JETP Lett.}, volume = {95}, issue = {12}, pages = {609}, year = {2012}, doi = {}, url = {http://jetpletters.ru/ps/0/article_29758.shtml}, note = {[Pisma v ZhETF 95, 689 (2012)]} }