@article{JETPL.110.217,
    title = {},
    author = {Volkov, M. K. and Pivovarov, A. A.},
    journal = {JETP Lett.},
    volume = {110},
    issue = {4},
    pages = {237},
    year = {2019},
    doi = {},
    url = {http://jetpletters.ru/ps/dx/10.1134/S0370274X1916001X},
    note = {[Pisma v ZhETF 110, 217 (2019)]}
}