@article{JETPL.106.214,
    title = {},
    author = {Dolganov, P. V. and Kats, E. I. and Dolganov, V. K.},
    journal = {JETP Lett.},
    volume = {106},
    issue = {4},
    pages = {229},
    year = {2017},
    doi = {},
    url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X17160056},
    note = {[Pisma v ZhETF 106, 214 (2017)]}
}