@article{PismaZhETF.19.665,
    title = {Optical pumping and nonlinear effects in the spectroscopy of the cesium $D_2$ line},
    author = {Bykovskii, Yu. A. and Velichanskii, V. L. and Egorov, V. K. and Zibrov, A. S. and Maslov, V. A.},
    journal = {Письма в ЖЭТФ},
    volume = {19},
    issue = {11},
    pages = {665},
    year = {1974},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_27116.shtml},
}