%0 Journal Article
%A M. A. Krasnosel'skii
%A E. A. Livshitz
%T Duality principles for boundary value problems
%J Doklady Akademii Nauk
%D 1967
%P 999-1001
%V 176
%N 5
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1967_176_5_a5/
%G ru
%F DAN_1967_176_5_a5