@article{PismaZhETF.6.597,
    title = {Self-stabilization of Laser Optic-oscillation Frequency by Nonlinear Absorption in Gas},
    author = {Letokhov, V. S.},
    journal = {Письма в ЖЭТФ},
    volume = {6},
    issue = {4},
    pages = {597},
    year = {1967},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25341.shtml},
}