@article{PismaZhETF.45.149,
    title = {An inequality for the density of condensate atoms in superfluid $^4He$},
    author = {Pitaevskii, L. P.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {45},
    issue = {3},
    pages = {149},
    year = {1987},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_18704.shtml},
}