@article{JETPL.103.147,
    title = {},
    author = {Volovik, G. E.},
    journal = {JETP Lett.},
    volume = {103},
    issue = {2},
    pages = {140},
    year = {2016},
    doi = {},
    url = {http://jetpletters.ru/ps/dx/10.7868/S0370274X16020132},
    note = {[Pisma v ZhETF 103, 147 (2016)]}
}