@article{PismaZhETF.18.497,
    title = {Concerning superconductivity in the sodium-ammonia system},
    author = {Dmitrenko, I. M. and Shchetkin, I. S.},
    journal = {Письма в ЖЭТФ},
    volume = {18},
    issue = {8},
    pages = {497},
    year = {1973},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_24029.shtml},
}