Oscillation criteria for nth-order nonlinear delay differential equations with a middle term

In this article, we establish some new criteria for the oscillation of nth-order nonlinear delay differential equations of the form (r(2)(t) (r(1)(t) (y((n-2))(t)(alpha))')' + p(t) (y((n-2))(t))(alpha) + q(t)f(y(g(t))) = 0, n even, provided that the second-order equation (r(2)(t)z')' + p(t)/r(1)(t)z = 0 is either nonoscillatory or oscillatory. Examples are given to illustrate the results. Copyright (C) 2015 John Wiley & Sons, Ltd.