@article{JETPL.105.245,
    title = {},
    author = {Volovik, G. E.},
    journal = {JETP Lett.},
    volume = {105},
    issue = {4},
    pages = {273},
    year = {2017},
    doi = {},
    url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X17040130},
    note = {[Pisma v ZhETF 105, 245 (2017)]}
}