1. Complex Analysis;Alfhors,1987
2. Elliptic Partial Differential Equations of Second Order;Gilbarg,1983
3. An estimate of the probability that a diffusion process hits a set of positive measure;Krylov;Soviet Math. Dokl.,1979
4. Principio di massimo per il rapporto di Hölder di soluzioni di equazioni ellittiche;Manselli,1993
5. Existence theory for certain ordinary differential equations with a monotone singularity;Miller;Proc. Amer. Math. Soc.,1967