@article{PismaZhETF.4.114,
    title = {Upper Limit of the Spectrum of Cosmic Rays},
    author = {Zatsepin, G. T. and Kuz'min, V. A.},
    journal = {Письма в ЖЭТФ},
    volume = {4},
    issue = {3},
    pages = {114},
    year = {1966},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_24846.shtml},
}