%0 Journal Article
%A D. Bularas
%A N. I. Vulpe
%A K. S. Sibirskii
%T The problem of the center “in the large” for a general quadratic
%J Doklady Akademii Nauk
%D 1990
%P 777-780
%V 311
%N 4
%U http://geodesic.mathdoc.fr/item/DAN_1990_311_4_a0/
%G ru
%F DAN_1990_311_4_a0