@article{PismaZhETF.16.29,
    title = {Possibility of Accelerating Many-level Systems and Multipole-moment Systems Moving in an Inverted Medium},
    author = {Gavrilov, V. P. and Kolomenskii, A. A.},
    journal = {Письма в ЖЭТФ},
    volume = {16},
    issue = {1},
    pages = {29},
    year = {1972},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_26719.shtml},
}