@article{JETPL.95.390,
    title = {},
    author = {Val?kov, V. V. and , },
    journal = {JETP Lett.},
    volume = {95},
    issue = {7},
    pages = {350},
    year = {2012},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_29672.shtml},
    note = {[Pisma v ZhETF 95, 390 (2012)]}
}