@article{PismaZhETF.50.351,
    title = {Effect of energy gap in the $high-T_c$ superconductor $Tm_{0.1}Y_{0.9}Ba_2Cu_3O_{6.9}$ on the widths of the transitions between the levels of the crystal field},
    author = {Goremychkin, E. A. and Osborn, R. and Taylor, A. D.},
    journal = {Письма в ЖЭТФ},
    volume = {50},
    issue = {8},
    pages = {351},
    year = {1989},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_17128.shtml},
}