@article{PismaZhETF.46.160,
    title = {Anisotropy of the surface stiffness of $He^4$ crystals},
    author = {Andreeva, O. A. and Keshishev, K. O.},
    journal = {Письма в ЖЭТФ},
    volume = {46},
    issue = {4},
    pages = {160},
    year = {1987},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_18540.shtml},
}