@article{JETPL.101.556,
    title = {},
    author = {,  and , },
    journal = {JETP Lett.},
    volume = {101},
    issue = {7},
    pages = {503},
    year = {2015},
    doi = {},
    url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X15070152},
    note = {[Pisma v ZhETF 101, 556 (2015)]}
}