%0 Journal Article
%A Liu, Yuji
%A Bai, Zhanbing
%A Gui, Zhanjie
%A Ge, Weigao
%T Positive periodic solutions of impulsive delay differential equations with sign-changing coefficient.
%J Portugaliae mathematica
%D 2004
%P 177-191
%V 61
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/PORMA_2004__61_2_51355/
%G en
%F PORMA_2004__61_2_51355