%0 Journal Article
%A I. A. Pasynkova
%T Letter to the editors ("The existence of families of periodic solutions of a system of $n$ second order differential equations in the resonance case'', Differencial'nye Uravnenija \textbf{5} (1969), 1984--1989)
%J Differencialʹnye uravneniâ
%D 1973
%P 192
%V 9
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1973_9_1_a29/
%G ru
%F DE_1973_9_1_a29