%0 Journal Article
%A K. S. Sibirskii
%T The problem of an algebraic integral in the case of the center
%J Differencialʹnye uravneniâ
%D 1972
%P 2211-2214
%V 8
%N 12
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1972_8_12_a12/
%G ru
%F DE_1972_8_12_a12