Oscillation of second-order nonlinear neutral differential equations

In this paper, some sufficient conditions for oscillation and nonoscillation are obtained for the second-order nonlinear neutral differential equation (∗)[x(t)−p(t)x(t−τ)]″+q(t)f(x(t−σ))=0,t⩾0, where 0⩽p(t)⩽1, q(t)⩾0, τ,σ>0.