@article{PismaZhETF.20.26,
    title = {Certain nonlinear properties of the single crystal $Ba_2NaNb_5O_{15}$},
    author = {Voronov, V. V. and Dorozhkin, L. M. and Kizel', V. A. and Maskaev, Yu. A.},
    journal = {Письма в ЖЭТФ},
    volume = {20},
    issue = {1},
    pages = {26},
    year = {1974},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_27176.shtml},
}