@article{PismaZhETF.33.236,
    title = {Method for studying the chemical composition of the primary cosmic radiation at and above $10^{17}$ eV},
    author = {Atrashkevich, V. B. and Kalmykov, N. N. and Khristiansen, G. B.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {33},
    issue = {4},
    pages = {236},
    year = {1981},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_22996.shtml},
}