@article{PismaZhETF.5.64,
    title = {Sum Rule for $\pi^0$, $\eta$, and $X^0$ Meson Interaction Constants},
    author = {Fainberg, V. Ya. and Fil'kov, L. V.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {5},
    issue = {2},
    pages = {64},
    year = {1967},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25098.shtml},
}