@article{PismaZhETF.70.740,
    title = {Variational procedure and generalized Lanczos recursion for small-amplitude classical oscillations},
    author = {Tsiper, E. V.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {70},
    issue = {11},
    pages = {740},
    year = {1999},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_14087.shtml},
}