*Article* **Sufficient Conditions for Oscillation of Fourth-Order Neutral Differential Equations with Distributed Deviating Arguments**

#### **Omar Bazighifan 1,2,†, Feliz Minhos 3,***<sup>∗</sup>***,† and Osama Moaaz 4,†**


Received: 14 February 2020; Accepted: 8 April 2020; Published: 11 April 2020

**Abstract:** Some new sufficient conditions are established for the oscillation of fourth order neutral differential equations with continuously distributed delay of the form *r* (*t*) ( *N*--- *x* (*t*))*<sup>α</sup>*- + - *b a q* (*t*, *ϑ*) *xβ* (*δ* (*t*, *ϑ*)) *dϑ* = 0, where *t* ≥ *t*0 and *Nx* (*t*) := *x* (*t*) + *p* (*t*) *x* (*ϕ* (*t*)). An example is provided to show the importance of these results.

**Keywords:** fourth-order differential equations; neutral delay; oscillation
