@article{PismaZhETF.29.311,
    title = {The theory of nuclear displacement of levels of a proton-antiproton atom},
    author = {Kudryavtsev, A. E. and Popov, V. S.},
    journal = {Письма в ЖЭТФ},
    volume = {29},
    issue = {5},
    pages = {311},
    year = {1979},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_22083.shtml},
}