@article{PismaZhETF.22.15,
    title = {Possibility of generating coherent optical radiation by an electron beam},
    author = {Gertsenshtein, N. E. and Kobzev, V. V.},
    journal = {Письма в ЖЭТФ},
    volume = {22},
    issue = {1},
    pages = {15},
    year = {1975},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_23245.shtml},
}