@article{PismaZhETF.5.29,
    title = {Frequency Doubling of Light in Ruby},
    author = {Belikova, T. P. and Sviridenkov, E. A.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {5},
    issue = {1},
    pages = {29},
    year = {1967},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25088.shtml},
}