@article{PismaZhETF.59.659,
    title = {Energy spectrum of a hierarchical superlattice with impurities in potential barriers},
    author = {Korol', A. N.},
    journal = {Письма в ЖЭТФ},
    volume = {59},
    issue = {10},
    pages = {659},
    year = {1994},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_19815.shtml},
}