@article{PismaZhETF.57.414,
    title = {Two-branch structure of the spectrum of elementary excitations of superfluid helium-4},
    author = {Blagoveshchenskii, N. M. and Bogoyavlenskii, I. V. and Karnatsevich, L. V. and Kozlov, Zh. A. and Kolobrodov, V. G. and Puchkov, A. V. and Skomorokhov, A. N.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {57},
    issue = {7},
    pages = {414},
    year = {1993},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_17807.shtml},
}