@article{PismaZhETF.26.591,
    title = {Observation of continuous coherent emission in methane at A = 3.39 $\mu$ m in spatially separated fields},
    author = {Bagaev, S. N. and Dychkov, A. S. and Chebolaev, V. P.},
    journal = {Письма в ЖЭТФ},
    volume = {26},
    issue = {8},
    pages = {591},
    year = {1977},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_20957.shtml},
}