Oscillatory and asymptotic behavior of a class of even order nonlinear neutral damped functional differential equations

It is considered that the oscillation and asymptotic behavior of the following even order nonlinear neutral damped functional differential equationsx(t)+ (t)x(τi(t))(n)+b(t)x(t)+ (t)x(τi(t))(n-1)+q(t)f(x(σ(t)))=0,t≥t0,two criteria for the oscillation of all its solutions are obtained,which extend some known results in the literature.Furthermore,two sufficient conditions for the oscillation and asymptotic behavior of every bounded solution are presented.