@article{PismaZhETF.17.296,
    title = {Concerning the "Hardness" of Crystalline Helium},
    author = {Keshishev, K. and Mezhov-Deglin, L. and Shal'nikov, A.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {17},
    issue = {6},
    pages = {296},
    year = {1973},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_27822.shtml},
}