@article{PismaZhETF.23.385,
    title = {Allowance for diffraction focusing of x rays in an elastically-bent crystal},
    author = {Petrashen', P. V. and Chukhovskii, F. N.},
    journal = {Письма в ЖЭТФ},
    volume = {23},
    issue = {7},
    pages = {385},
    year = {1976},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_27530.shtml},
}