@article{PismaZhETF.30.308,
    title = {Coherent frequency doubling in nonlinear nonhomogeneous elements},
    author = {Andreev, N. F. and Bespalov, V. I. and Kiselev, A. M. and Matveev, A. Z. and Pasmanik, G. A.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {30},
    issue = {5},
    pages = {308},
    year = {1979},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_21753.shtml},
}