“…x +φ(x,ẋ)ẍ + g(ẋ) + h(x) = p (t, x,ẋ,ẍ), (1) in which φ, g, h and p depend on the arguments displayed explicitly and dots denote differentiation with respect to t. Moreover, the existence and the uniqueness of solutions of (1) will be assumed. Equations of the form (1) do arise in some aspect of applied sciences such as after effect, nonlinear oscillations, biological systems and equations with deviating arguments (see [1], [2] and [3]) and an effective method for studying the qualitative properties of solutions of such nonlinear equations is still the Lyapunov's direct method (see [4], [5], [6], [7], [8], [9], [10], [11], [12]). Many of these results on stability, boundedness, convergence of solutions exist for more general or special cases of (1) and are summarized in [13].…”