| 摘 要： | Recently the authors have studied the oscillations of some neutral differential difference equations and obtained very good results (see 1—4]). In this paper we consider the oscillations of the neutral differential difference equationd/dtx(t)+sum from i=1 px(t-τ)+sum form j=1 to n qx(t-σ)=0, t≥t,] (*)where p, τ, q and σ (i=1, 2, …, m; j=1, 2, …, n) are positive constants. Some sufficient conditions for all solutions of (*) to oscillate are obtained. And in some ease we give neeessaxy and sufficient conditions for (*) to oscillate.
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