Degenerate elliptic equations with nonlinear boundary conditions and measures data

In this paper we study the questions of existence and uniqueness of solutions for equations of type -div a(x, Du) + gamma(u) (sic) mu(1), posed in an open bounded subset Omega of R(N), with nonlinear boundary conditions of the form a(x, Du).eta+beta(u) (sic) mu(2). The nonlinear elliptic operator div a(x, Du) is modeled on the p-Laplacian operator Delta p(u) = div (vertical bar Du vertical bar(p-2)Du), with p > 1, gamma and beta are maximal monotone graphs in R(2) such that 0 is an element of gamma(0) boolean AND beta(0) and the data mu(1) and mu(2) are measures.