and Applied Analysis 3 where τ, p, g : R → R are continuous functions, B, δ, C are constants, τ and p are T -periodic, C/ 0, |B|/ 1, and T > 0. Zhou and Zhang 8 extended the results in 1 to the higher-order neutral functional differential equation with positive and negative coefficients: d dtn [ x t px t − τ ] −1 n 1 P t x t − σ −Q t x t − δ 0, t ≥ t0, 1.9 where p ∈ R \ {±1}, τ, σ, δ ∈ R and P,...