%0 Journal Article
%A Ling Zhengqiu
%T Perturbation of solutions and perturbation of eigenvalues and eigenfunctions of second-order elliptic equations under 

%J Doklady Akademii Nauk
%D 1964
%P 784-787
%V 157
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1964_157_4_a7/
%G ru
%F DAN_1964_157_4_a7