@article{DE_1978_14_12_a23,
     author = {S. G. Kondratenya and V. G. Linevich},
     title = {On the question of classes of first-order differential equations with stationary critical singular points},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2276--2278},
     publisher = {mathdoc},
     volume = {14},
     number = {12},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1978_14_12_a23/}
}