@article{PismaZhETF.47.128,
    title = {Dirac quantization conditions and the three-cocycle},
    author = {Ryzhov, A. B.},
    journal = {Письма в ЖЭТФ},
    volume = {47},
    issue = {3},
    pages = {128},
    year = {1988},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_16470.shtml},
}