@article{DE_1991_27_2_a2,
     author = {V. I. Rozhkov},
     title = {Periodic solutions of linear singularly perturbed systems with certain singularities},
     journal = {Differencialʹnye uravneni\^a},
     pages = {200--207},
     publisher = {mathdoc},
     volume = {27},
     number = {2},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1991_27_2_a2/}
}