UDC 517.925Asymptotic representations are found for solutions of nonautonomous second-order differential equations with nonlinearities close to power-type nonlinearities.In the present paper, we consider the nonlinear differential equationBy virtue of the first condition in (2), every function ϕ i , i ∈ {0, 1}, is close, in a certain sense, to a power function, namely, it has the form ϕWe say that a function ϕ i (z), i ∈ {0, 1}, satisfies condition S i if, for any continuously differentiable function L :. 2 For Yi = +∞ (Yi = −∞), we suppose that y 0 i > 0 (y 0 i < 0), respectively.