@article{JETPL.94.921,
    title = {},
    author = {,  and , },
    journal = {JETP Lett.},
    volume = {94},
    issue = {12},
    pages = {840},
    year = {2011},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_29602.shtml},
    note = {[Pisma v ZhETF 94, 921 (2011)]}
}