%0 Journal Article
%A N. V. Efimov
%T The validity of Hilbert's theorem on surfaces of constant negative curvature
%J Doklady Akademii Nauk
%D 1961
%P 1283-1286
%V 136
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1961_136_6_a5/
%G ru
%F DAN_1961_136_6_a5