@article{PismaZhETF.7.324,
    title = {Experimental Observation of Scattering of Light by Light in a Solid, Accompanied by a Change in Frequency},
    author = {Grinberg, E. N. and Ryvkin, S. M. and Fishman, I. M. and Yaroshetskii, I. D.},
    journal = {Письма в ЖЭТФ},
    volume = {7},
    issue = {9},
    pages = {324},
    year = {1968},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25656.shtml},
}