@article{PismaZhETF.4.441,
    title = {Observation of Generation at the Sum Frequency in Electro-optic Nonlinear  Crystals},
    author = {Gol'din, Yu. A. and Dmitriev, V. G. and Tarasov, V. K. and Shkunov, N. V.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {4},
    issue = {11},
    pages = {441},
    year = {1966},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25061.shtml},
}