@article{PismaZhETF.5.70,
    title = {Calculation of $K_1$ and $K_2$ Mass Difference},
    author = {Vainshtein, A. I. and Khriplovich, I. B.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {5},
    issue = {2},
    pages = {70},
    year = {1967},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25100.shtml},
}