@article{PismaZhETF.5.335,
    title = {Dependence of the Width of a Self-focusing Light Beam on the Power},
    author = {Yankauskas, Z. K.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {5},
    issue = {9},
    pages = {335},
    year = {1967},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25187.shtml},
}