@article{DE_1995_31_4_a1,
     author = {N. V. Voropaeva and V. A. Sobolev},
     title = {A constructive method for splitting nonlinear singularly perturbed differential systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {569--578},
     publisher = {mathdoc},
     volume = {31},
     number = {4},
     year = {1995},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1995_31_4_a1/}
}