摘要：In the paper, fourth-order delay differential equations of the form
(r3(r2(r1y′)′)′)′(t)+q(t)y(τ(t))=0
under the assumption
∫∞t0dtri(t)<∞,i=1,2,3,
are investigated. Our newly proposed approach allows us to greatly reduce a number of conditions ensuring that all solutions of the studied equation oscillate. An example is also presented to test the strength and applicability of the results obtained.
