%0 Journal Article
%A Li,  Yongjin
%T Existence of periodic solutions for second-order neutral differential equations
%J Electronic journal of differential equations
%D 2005
%V 2005
%U http://geodesic.mathdoc.fr/item/EJDE_2005__2005__a75/
%G en
%F EJDE_2005__2005__a75