@article{EJDE_2007__2007__a69,
     author = {Liu,  Li and Li,  Xiangao and Zhuang,  Kejun},
     title = {Bifurcation analysis on a delayed {SIS} epidemic model with stage structure},
     journal = {Electronic journal of differential equations},
     year = {2007},
     volume = {2007},
     zbl = {1140.34427},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2007__2007__a69/}
}