@article{PismaZhETF.50.25,
    title = {Anisotropy of the optical characteristics of the superconducting  $YBa_2Cu_3O_{7-\delta}$ crystals and of the Bi-Sr-Ca-Cu-O system},
    author = {Petrov, M. P. and Grachev, A. I. and Krasin'kova, M. V. and Nechitaflov, A. A. and Poborchii, V. V. and Shagin, S. I. and Miridonov, S. V.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {50},
    issue = {1},
    pages = {25},
    year = {1989},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_17031.shtml},
}