The aim of this paper is to study the oscillatory behavior of general third order neutral delay differential equations by using
a generalized Riccati transformation. New sufficient conditions for oscillations of solutions are established.The obtained results extend
and improve some known results in the literature. Illustrative examples are given to support our main results. There has been considerable interest in studying the
oscillation of solutions of neutral delay differential
equations in the last two decades. Although the oscillation
of third-order equations has received less attentions
relatively comparing with those of second-order, however
there is an increasing interest in studying the oscillation
of neutral delay third-order equations ( see [2], [4], [8],
[10]).