@article{PismaZhETF.34.511,
    title = {Observation of an excited state of a pion: a new pseudoscalar meson},
    author = {Bellini, G. and Vasilevskii, I. M. and Vegni, G. and Vishnyakov, V. V. and Di Corato, M. and Zaimidoroga, O. A. and Ivan'shchin, Yu. I. and Lytkin, L. K. and Palombo, F. and Pernegr, J. and Sala, A. and Sala, S. and Sychkov, S. Ya. and Tyapkin, A. A. and Frabetti, P. -L.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {34},
    issue = {9},
    pages = {511},
    year = {1981},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_23441.shtml},
}