@article{PismaZhETF.57.30,
    title = {On the generalized energy principle for the flute perturbations},
    author = {Lansky, I. M. and Ryutov, D. D.},
    journal = {πΙΣΨΝΑ Χ φότζ},
    volume = {57},
    issue = {1},
    pages = {30},
    year = {1993},
    doi = {},
    url = {http://jetpletters.ru/ps/0/article_4577.shtml},
}