@article{PismaZhETF.26.129,
    title = {Helical density waves in flat galaxies-moving solitons},
    author = {Mikhailovskii, A. B. and Petviashvili, V. I. and Fridman, A. M.},
    journal = {Письма в ЖЭТФ},
    volume = {26},
    issue = {3},
    pages = {129},
    year = {1977},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_20817.shtml},
}