@article{DAN_1957_117_6_a0,
     author = {V. M. Volosov},
     title = {Non-linear oscillations with one degree of freedom of a system with slowly varying parameters},
     journal = {Doklady Akademii Nauk},
     pages = {927--930},
     publisher = {mathdoc},
     volume = {117},
     number = {6},
     year = {1957},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1957_117_6_a0/}
}