@article{PismaZhETF.7.117,
    title = {Ring Ruby Laser for Ultrashort Pulses},
    author = {Krasyuk, I. K. and Pashinin, P. P. and Prokhorov, A. M.},
    journal = {Письма в ЖЭТФ},
    volume = {7},
    issue = {4},
    pages = {117},
    year = {1968},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25592.shtml},
}