%0 Journal Article
%A Cheng, Sui Sun
%A Zhang, Guang
%T Existence of positive periodic solutions for non-autonomous functional differential equations
%J Electronic Journal of Differential Equations
%D 2001
%V 2001
%I mathdoc
%U http://geodesic.mathdoc.fr/item/EJDE_2001__2001__a3/
%G en
%F EJDE_2001__2001__a3