%0 Journal Article
%A G. A. Utkin
%T Topological classification of non-singular fourth-order surfaces
%J Doklady Akademii Nauk
%D 1967
%P 40-43
%V 175
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1967_175_1_a9/
%G ru
%F DAN_1967_175_1_a9