@article{PismaZhETF.2.34,
    title = {Casimir Operators for the Orthogonal and Symplectic Groups},
    author = {Perelomov, A. M. and Popov, V. S.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {2},
    issue = {1},
    pages = {34},
    year = {1965},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_24451.shtml},
}