@article{DE_1992_28_12_a20,
     author = {M. G. Medvedeva},
     title = {Investigation of the stability of systems that have invariant toroidal manifolds},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2169--2172},
     publisher = {mathdoc},
     volume = {28},
     number = {12},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1992_28_12_a20/}
}