@article{PismaZhETF.7.137,
    title = {Is One of the Lepton Quantum Numbers Multiplicative?},
    author = {Nguyen Van Hieu,  and Pontecorvo, B.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {7},
    issue = {4},
    pages = {137},
    year = {1968},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25598.shtml},
}