Electronic Journal of Differential Equations, Vol. 2004(2004), No. 144, pp. 1-18. Title: Quasilinear elliptic systems in divergence form with weak monotonicity and nonlinear physical data Authors: Fabien Augsburger (Univ. of Fribourg, Switzerland) Norbert Hungerbuehler (Univ. of Fribourg, Switzerland) Abstract: We study the quasilinear elliptic system \[ -\mathop{\rm div}\sigma(x,u,Du) =v(x)+f(x,u)+\mathop{\rm div}g(x,u) \] on a bounded domain of $\mathbb{R}^n$ with homogeneous Dirichlet boundary conditions. This system corresponds to a diffusion problem with a source $v$ in a moving and dissolving substance, where the motion is described by $g$ and the dissolution by $f$. We prove existence of a weak solution of this system under classical regularity, growth, and coercivity conditions for $\sigma$, but with only very mild monotonicity assumptions. Submitted August 16, 2004. Published December 7, 2004. Math Subject Classifications: 35J60. Key Words: Young measure; noninear elliptic systems.