%0 Journal Article
%A V. V. Basov
%A A. V. Skitovich
%T A Generalized Normal Form and Formal Equivalence of Two-Dimensional Systems with Quadratic Zero Approximation: I
%J Differencialʹnye uravneniâ
%D 2003
%P 1016-1029
%V 39
%N 8
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_2003_39_8_a1/
%G ru
%F DE_2003_39_8_a1