@article{PismaZhETF.34.148,
    title = {Study of the neutrino mass in a double $\beta$ decay},
    author = {Zel'dovich, Ya. B. and Khlopov, M. Yu.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {34},
    issue = {3},
    pages = {148},
    year = {1981},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_23152.shtml},
}