@article{PismaZhETF.20.135,
    title = {Diagonality of the electron mass operators in a constant field},
    author = {Ritus, V. I.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {20},
    issue = {2},
    pages = {135},
    year = {1974},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_27206.shtml},
}