%0 Journal Article
%A ZHANG, LIANG
%A TANG, XIANHUA
%T PERTURBATIONS FROM INDEFINITE SYMMETRIC ELLIPTIC BOUNDARY VALUE PROBLEMS
%J Glasgow mathematical journal
%D 2017
%P 635-648
%V 59
%N 3
%U http://geodesic.mathdoc.fr/articles/10.1017/S0017089516000446/
%R 10.1017/S0017089516000446
%F 10_1017_S0017089516000446