@article{PismaZhETF.20.664,
    title = {Coherent amplification of light in ruby at $105^\circ$ K},
    author = {Leontovich, A. M. and Mozharovskii, A. M.},
    journal = {Письма в ЖЭТФ},
    volume = {20},
    issue = {10},
    pages = {664},
    year = {1974},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_27374.shtml},
}