Three solutions for a class of quasilinear elliptic systems involving the (p,q)(p,q)-Laplacian

The existence of at least three weak solutions is established for a class of quasilinear elliptic systems involving the (p,q)(p,q)-Laplacian with Dirichlet boundary condition. Our technical approach is based on the three-critical-points theorem obtained by B. Ricceri.