@article{JETPL.104.446,
    title = {},
    author = {,  and ,  and ,  and , },
    journal = {JETP Lett.},
    volume = {104},
    issue = {6},
    pages = {431},
    year = {2016},
    doi = {},
    url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X16180132},
    note = {[Pisma v ZhETF 104, 446 (2016)]}
}