@article{DE_1992_28_6_a1,
     author = {Z. U. Blyagoz and V. A. Teshev},
     title = {A frequency criterion for stability in the large of periodic solutions of nonlinear nonautonomous systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {925--930},
     publisher = {mathdoc},
     volume = {28},
     number = {6},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1992_28_6_a1/}
}