@article{PismaZhETF.41.55,
    title = {Distribution of energy levels of quantum systems},
    author = {Bogomol'nyi, E. B.},
    journal = {Письма в ЖЭТФ},
    volume = {41},
    issue = {2},
    pages = {55},
    year = {1985},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_21917.shtml},
}