Problem solving Nonlinear systems Time scales p-Laplacian Boundary value problems Coincidence degree Elliptic system Lyapunov inequality Periodic solutions Radial functions Eigenvalue bounds Landesman-Lazer conditions Nirenberg condition Resonance Sobolev spaces Theorem proving p-Laplacian systems Asymptotic of eigenvalues Boundary conditions Embedding theorems Functions Lazer-Leach conditions Multiple solutions Nonlinear equations P-Laplace operator Power weights Quasilinearization method Topological methods Upper and lower solutions Variational methods