“…In the case where (X, ) is partially ordered complete metric space, taking E (G) = {(x, y) ∈ X × X : x y}, the functions ϕ (t) = t and ψ (t) = kt, for t ∈ [0, ∞) and k ∈ [0, 1), Theorem 2 generalize and improve the results obtained by Bhaskar and Lakshmikantham ( [1], Theorem 2.1) and Chifu and Petrusel ( [9], Theorem 2.1). If we take the function ψ (t) = ϕ (t) − ψ 1 (t), for t ∈ [0, ∞), where ψ 1 ∈ Ψ, Theorem 2 generalize the results given by Luong and Thuan ( [3], Theorem 2.1).…”