@article{PismaZhETF.31.56,
    title = {Population inversion of the spin states of $Cr^{3+}$ in silicon due to unpolarized optical pumping},
    author = {Konchits, A. A. and Zaritskii, I. M. and Semenov, Yu. G. and Shanina, B. D. and Vikhnin, V. S. and Krulikovskii, B. K.},
    journal = {Письма в ЖЭТФ},
    volume = {31},
    issue = {1},
    pages = {56},
    year = {1980},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_20238.shtml},
}