@article{DE_1980_16_8_a8,
     author = {A. M. Samoilenko},
     title = {Necessary conditions for the existence of invariant tori of linear extensions of dynamical systems on a torus},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1427--1437},
     publisher = {mathdoc},
     volume = {16},
     number = {8},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1980_16_8_a8/}
}