%0 Journal Article
%A Yik-Man Chiang
%A Shi-An Gao
%T On a problem in complex oscillation theory of periodic second order linear differential equations and some related perturbation results
%J Annales Fennici Mathematici
%D 2002
%P 273-290
%V 27
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/AFM_2002_27_2_a1/
%G en
%F AFM_2002_27_2_a1