%0 Journal Article
%A P. E. Sobolevskii
%T On second-order differential equations in a Banach space
%J Doklady Akademii Nauk
%D 1962
%P 774-777
%V 146
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1962_146_4_a9/
%G ru
%F DAN_1962_146_4_a9