where Ω is a bounded smooth domain of R N with 0 ∈ Ω, 1 < p, q < N, 0 ≤ a < N −p p , 0 ≤ b < N −q q and α i , β i , c i are positive parameters. Here M i , A i , B i , f, g, h, k are continuous functions and we discuss the existence of positive solution when they satisfy certain additional conditions. Our approach is based on the sub and super solutions method.