@article{PismaZhETF.7.341,
    title = {Admissible Mass Distributions of Unstable Particles},
    author = {Khalfin, L. A.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {7},
    issue = {9},
    pages = {341},
    year = {1968},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25661.shtml},
}