@article{PismaZhETF.85.163,
    title = {Constraining  the fraction of primary gamma rays at ultra-high energies from the muon data of the Yakutsk extensive air shower array},
    author = {Glushkov, A. V. and Gorbunov, D. S. and Makarov, I. T. and Pravdin, M. I. and Rubtsov, G. I. and Sleptsov, I. E. and Troitsky, S. V.},
    journal = {Письма в ЖЭТФ},
    volume = {85},
    issue = {3},
    pages = {163},
    year = {2007},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_16374.shtml},
}