@article{PismaZhETF.52.905,
    title = {Direct observation of optical absorption by excess electrons in liquid helium},
    author = {Parshin, A. Ya. and Pereverzev, S. V.},
    journal = {Письма в ЖЭТФ},
    volume = {52},
    issue = {5},
    pages = {905},
    year = {1990},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_17493.shtml},
}