@article{PismaZhETF.60.410,
    title = {Point-contact and tunneling spectroscopy of $YBa_2Cu_3O_{7-x}$ and $YbBa_2Cu_3O_{7-x}$ (90-K phase) single crystals},
    author = {Aminov, B. A. and Wehler, D. and Muller, G. and Piel, H. and Hein, M. A. and Heinrichs, H. and Brandt, N. B. and Hu, C. S. and Ponomarev, Ya. G. and Tsokur, E. B. and Chesnokov, S. N. and Yusupov, K. Ch. and Yarygin, A. V. and Winzer, K. and Rosier, K. and Wolf, T.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {60},
    issue = {6},
    pages = {410},
    year = {1994},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_20365.shtml},
}