@article{JETPL.99.623,
    title = {},
    author = {,  and ,  and , },
    journal = {JETP Lett.},
    volume = {99},
    issue = {9},
    pages = {540},
    year = {2014},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_30776.shtml},
    note = {[Pisma v ZhETF 99, 623 (2014)]}
}