@article{DE_2006_42_3_a2,
     author = {V. V. Basov},
     title = {A generalized normal form and formal equivalence of two-dimensional systems with quadratic zero approximation: {III}},
     journal = {Differencialʹnye uravneni\^a},
     pages = {308--319},
     publisher = {mathdoc},
     volume = {42},
     number = {3},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2006_42_3_a2/}
}