@article{PismaZhETF.9.507,
    title = {Attempts at Observing Vacancions in $He^4$ Crystals},
    author = {Andreev, A. and Keshishev, K. and Mezhov-Deglin, L. and Shal'nikov, A.},
    journal = {Письма в ЖЭТФ},
    volume = {9},
    issue = {9},
    pages = {507},
    year = {1969},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_26787.shtml},
}