PageHeader : Funkcialaj Ekvacioj, 36 (1993) 123-141 Title : Viscosity Solutions of Nonlinear Second Order Elliptic PDEs Title : Associated with Impulse Control Problems AuthorInfo : By AuthorInfo : Katsuyuki ISHII AuthorInfo : (Kobe University, Japan) section : 1. Introduction section : 2. Preliminaries section : 3. Comparison principle of viscosity solutions section : 4. Existence of viscosity solutions section : References