@article{PismaZhETF.23.624,
    title = {Spreading of phonon beam in superfluid helium},
    author = {Laikhtman, B. D. and Lomakin, A. V.},
    journal = {Письма в ЖЭТФ},
    volume = {23},
    issue = {11},
    pages = {624},
    year = {1976},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_27594.shtml},
}