@article{JETPL.96.557,
    title = {},
    author = {,  and ,  and ,  and , },
    journal = {JETP Lett.},
    volume = {96},
    issue = {8},
    pages = {507},
    year = {2012},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_30002.shtml},
    note = {[Pisma v ZhETF 96, 557 (2012)]}
}