@article{PismaZhETF.51.389,
    title = {Phase conjugation during second-harmonic generation in few mode fibers},
    author = {Zel'dovich, B. Ya. and Kapitskii, Yu. E.},
    journal = {Письма в ЖЭТФ},
    volume = {51},
    issue = {8},
    pages = {389},
    year = {1990},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_17282.shtml},
}