@article{PismaZhETF.22.275,
    title = {Impurities in singlet magnets},
    author = {Shender, E. F.},
    journal = {Письма в ЖЭТФ},
    volume = {22},
    issue = {5},
    pages = {275},
    year = {1975},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_23318.shtml},
}