@article{PismaZhETF.4.303,
    title = {A Mechanism Ensuring Level Population Inversion in $C0_2$ Lasers},
    author = {Sobolev, N. N. and Sokovikov, V. V.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {4},
    issue = {8},
    pages = {303},
    year = {1966},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25012.shtml},
}