@article{PismaZhETF.14.217,
    title = {Layered Compounds of $NiCl_2$ and $CoCl_2$ with Graphite as Two-dimensional Heisenberg Ferromagnets},
    author = {Karimov, Yu. S. and Vol'pin, M. E. and Novikov, Yu. N.},
    journal = {Письма в ЖЭТФ},
    volume = {14},
    issue = {4},
    pages = {217},
    year = {1971},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_24591.shtml},
}