@article{JETPL.107.668,
    title = {},
    author = {Boev, M. V. and Kovalev, V. M.},
    journal = {JETP Lett.},
    volume = {107},
    issue = {10},
    pages = {635},
    year = {2018},
    doi = {},
    url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X18100090},
    note = {[Pisma v ZhETF 107, 668 (2018)]}
}