@article{JETPL.109.769,
    title = {},
    author = {Val?kov, V. V. and , },
    journal = {JETP Lett.},
    volume = {109},
    issue = {11},
    pages = {736},
    year = {2019},
    doi = {},
    url = {http://jetpletters.ru/ps/dx/10.1134/S0370274X19110092},
    note = {[Pisma v ZhETF 109, 769 (2019)]}
}