“…For λ = 0, f (x) = h(x) ≡ 1, Ambrosetti et al [1] considered equation (1) on bounded domain with concave-convex nonlinearity. In [14], Lin studied the equation with s = 1 has a positive ground stste solution and for λ large enough, the equation admits at least k + 1 positive solutions. For more results of the case s = 1, we refer the readers to the papers [14,27,8,25] and the references therein.…”