@article{DAN_1962_143_2_a0,
     author = {E. G. Belaga},
     title = {The reducibility of a system of ordinary differential equations in the neighborhood of a conditionally periodic motion},
     journal = {Doklady Akademii Nauk},
     pages = {255--258},
     publisher = {mathdoc},
     volume = {143},
     number = {2},
     year = {1962},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1962_143_2_a0/}
}