@article{JETPL.99.552,
    title = {},
    author = {Volovik, G. E. and Zubkov, M. A.},
    journal = {JETP Lett.},
    volume = {99},
    issue = {8},
    pages = {481},
    year = {2014},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_30764.shtml},
    note = {[Pisma v ZhETF 99, 552 (2014)]}
}