@article{PismaZhETF.15.211,
    title = {Bound States of Excitations in a Bose System with a Condensate},
    author = {Nepomnyashchii, Yu. A.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {15},
    issue = {4},
    pages = {211},
    year = {1972},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_26531.shtml},
}