@article{PismaZhETF.10.113,
    title = {"Banana" Self Focusing of Beams},
    author = {Askar'yan, G. A. and Studenov, V. B.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {10},
    issue = {3},
    pages = {113},
    year = {1969},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25696.shtml},
}