@article{PismaZhETF.87.736,
    title = {Phonons in magnon superfluid and symmetry breaking field},
    author = {Volovik, G. E.},
    journal = {Письма в ЖЭТФ},
    volume = {87},
    issue = {11},
    pages = {736},
    year = {2008},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_28096.shtml},
}