@article{JETPL.111.50,
    title = {},
    author = {,  and , },
    journal = {JETP Lett.},
    volume = {111},
    issue = {1},
    pages = {55},
    year = {2020},
    doi = {},
    url = {http://jetpletters.ru/ps/dx/10.31857/S0370274X20010105},
    note = {[Pisma v ZhETF 111, 50 (2020)]}
}