@article{PismaZhETF.33.542,
    title = {Many-photon parametric resonant frequency up-conversion in a nonmonochromatic pump field},
    author = {Iskanderov, N. A. and Kudryashov, V. A. and Matveev, I. N. and Ustinov, N. D.},
    journal = {Письма в ЖЭТФ},
    volume = {33},
    issue = {10},
    pages = {542},
    year = {1981},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_23077.shtml},
}