@article{PismaZhETF.51.256,
    title = {Second lasing threshold: onset of coherence},
    author = {Bykov, V. P.},
    journal = {Письма в ЖЭТФ},
    volume = {51},
    issue = {5},
    pages = {256},
    year = {1990},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_17244.shtml},
}