@article{DE_2006_42_2_a16,
     author = {E. K. Makarov},
     title = {On the properties of bogdanov perturbations of linear differential systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {275--277},
     publisher = {mathdoc},
     volume = {42},
     number = {2},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2006_42_2_a16/}
}