@article{SJIM_2002_5_2_a8,
     author = {L. I. Kononenko},
     title = {On the smoothness of slow surfaces of singularly perturbed systems},
     journal = {Sibirskij \v{z}urnal industrialʹnoj matematiki},
     pages = {109--125},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {2002},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/SJIM_2002_5_2_a8/}
}