@article{PismaZhETF.28.65,
    title = {Topological singularities on the surface of an ordered system},
    author = {Volovik, G. E.},
    journal = {Письма в ЖЭТФ},
    volume = {28},
    issue = {2},
    pages = {65},
    year = {1978},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_23826.shtml},
}