@article{DAN_1975_221_2_a12,
     author = {L. P. Osipkov},
     title = {Small vertical oscillations in the field of rotationally symmetric potential},
     journal = {Doklady Akademii Nauk},
     pages = {309--311},
     publisher = {mathdoc},
     volume = {221},
     number = {2},
     year = {1975},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1975_221_2_a12/}
}