%0 Journal Article %A Liu, Li %A Li, Xiangao %A Zhuang, Kejun %T Bifurcation analysis on a delayed SIS epidemic model with stage structure %J Electronic Journal of Differential Equations %D 2007 %V 2007 %I mathdoc %U http://geodesic.mathdoc.fr/item/EJDE_2007__2007__a169/ %G en %F EJDE_2007__2007__a169