@article{VNGU_2009_9_4_a4,
     author = {L. I. Kononenko},
     title = {Relaxations in {Singularly} {Perturbed} {Planar} {Systems}},
     journal = {Sibirskij \v{z}urnal \v{c}istoj i prikladnoj matematiki},
     pages = {45--50},
     publisher = {mathdoc},
     volume = {9},
     number = {4},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VNGU_2009_9_4_a4/}
}