@article{PismaZhETF.32.603,
    title = {Propagation of an amplifying pulse in a two-level medium},
    author = {Zakharov, V. E.},
    journal = {Письма в ЖЭТФ},
    volume = {32},
    issue = {10},
    pages = {603},
    year = {1980},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_21809.shtml},
}