The aim of this paper is to study the oscillatory properties of 4th-order neutral differential equations. We obtain some oscillation criteria for the equation by the theory of comparison. The obtained results improve well-known oscillation results in the literate. Symmetry plays an important role in determining the right way to study these equation. An example to illustrate the results is given.

中文翻译：

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带时滞自变量的四阶中性微分方程的一些新振荡结果

本文的目的是研究四阶中性微分方程的振荡特性。我们通过比较理论获得了方程的一些振荡标准。获得的结果改善了文学中众所周知的振荡结果。对称性在确定研究这些方程的正确方法方面起着重要作用。给出了一个例子来说明结果。