“…When α = 0, λ = 1, problem (1.2) becomes a second-order Kirchhoff type equation; these have been studied extensively and many classical results have been obtained in the past few years. For example, Sun et al [ST19] considered problem (1.2) with M (s) = a + bs and f (x, u) = f (x) u γ + g(x)u q , where 0 < f (x) ∈ L 1 (Ω), 0 ≤ g(x) ∈ L ∞ (Ω), q ∈ (0, 1) and γ > 1. By using Ekeland's variational principle on some subset of H 1 0 (Ω) to overcome the difficulty caused by the strongly singular term, they obtained an optimal condition for the existence of positive solutions.…”