@article{JETPL.97.253,
    title = {},
    author = {Kagan, M. Yu. and Val?kov, V. V. and Mitskan, V. A. and Korovushkin, M. M.},
    journal = {JETP Lett.},
    volume = {97},
    issue = {4},
    pages = {226},
    year = {2013},
    doi = {},
    url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X13040127},
    note = {[Pisma v ZhETF 97, 253 (2013)]}
}