@article{PismaZhETF.7.70,
    title = {Two-photon Decay of 2s Level of Hydrogen},
    author = {Zon, B. A. and Rapoport, L. P.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {7},
    issue = {2},
    pages = {70},
    year = {1968},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_25578.shtml},
}