@article{JETPL.102.216,
    title = {},
    author = {Molotkov, S. N. and Ryzhkin, M. I.},
    journal = {JETP Lett.},
    volume = {102},
    issue = {3},
    pages = {189},
    year = {2015},
    doi = {},
    url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X15150102},
    note = {[Pisma v ZhETF 102, 216 (2015)]}
}