Quasi-linear degenerate elliptic problems with L1 data

We prove existence and uniqueness of a solution for a class of quasi-linear problems with L1 data. The diffusion matrix A(x,u) is allowed to degenerate with respect to the unknown u. We obtain uniqueness of the solution under a weak assumption on A(x,u) that permits to consider highly oscillating or/and increasing coefficients (with respect to u).