@article{JETPL.97.469,
    title = {},
    author = {,  and , },
    journal = {JETP Lett.},
    volume = {97},
    issue = {7},
    pages = {404},
    year = {2013},
    doi = {},
    url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X13070060},
    note = {[Pisma v ZhETF 97, 469 (2013)]}
}