@article{DE_1982_18_5_a7,
     author = {N. A. Lukashevich},
     title = {Third-order equations without fixed critical points},
     journal = {Differencialʹnye uravneni\^a},
     pages = {778--785},
     publisher = {mathdoc},
     volume = {18},
     number = {5},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1982_18_5_a7/}
}