@article{DE_1967_3_11_a2,
     author = {Yu. N. Bibikov and V. A. Pliss},
     title = {The existence of invariant tori in the neighborhood of the zero solution of a system of ordinary differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1864--1881},
     publisher = {mathdoc},
     volume = {3},
     number = {11},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1967_3_11_a2/}
}