@article{DAN_1988_303_3_a6,
     author = {M. Imanaliev and P. S. Pankov},
     title = {Singularly perturbed systems of ordinary differential equations in},
     journal = {Doklady Akademii Nauk},
     pages = {546--549},
     publisher = {mathdoc},
     volume = {303},
     number = {3},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1988_303_3_a6/}
}