@article{PismaZhETF.47.317,
    title = {Study of the conductivity of $YBa_2Cu_3O_{7-x}$, single crystals in a wide frequency range},
    author = {Kotyuzhanskii, B. Ya. and Svistov, L. E.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {47},
    issue = {6},
    pages = {317},
    year = {1988},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_16516.shtml},
}