Citation: Hw. Hethcote et P. Vandendriessche, AN SIS EPIDEMIC MODEL WITH VARIABLE POPULATION-SIZE AND A DELAY, Journal of mathematical biology, 34(2), 1995, pp. 177-194
Citation: Js. Zhou et Hw. Hethcote, POPULATION-SIZE DEPENDENT INCIDENCE IN MODELS FOR DISEASES WITHOUT IMMUNITY, Journal of mathematical biology, 32(8), 1994, pp. 809-834