General decay of solutions for a nonlinear system of viscoelastic wave equations with degenerate damping and source terms

The initial boundary value problem for a system of nonlinear viscoelastic wave equations with degenerate damping and source terms in a bounded domain is considered. Under some assumptions on the relaxation functions, degenerate damping and source terms, we obtain the decay rate of the energy function for certain initial data. This improves earlier results in the literature.