1. D. G.Aronson,Non linear diffusion problems, in «Free boundary problems: theory and application (Fasano-Primicerio, eds.), Research notes in mathematics,79 (1983), pp. 135–150.
2. D. G. Aronson -Ph. Benilan,Regularité des solutions de l'équation des milieux poreux dans
R
n, Comptes Rendues (Hebdomaire) Acad. Sci. Paris, S.A.,288 (1979), p. 103.
3. I.Bracali,Un modello di epidemia a due popolazioni (to appear).
4. V. Capasso -G. Serio,A generalization of the Kermack-McKendrick deterministic model, Math. Biosc.,42 (1978), pp. 43–61.
5. A.Friedman,Partial differential equations of parabolic type, Prentice-Hall, 1964.