@article{PismaZhETF.58.889,
    title = {Polaron conductivity mechanism in $PrBa_2Cu_3O_{6.9}$},
    author = {Varyukhin, S. V. and Parfenov, O. E.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {58},
    issue = {11},
    pages = {889},
    year = {1993},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_18024.shtml},
}