“…We have also seen that the class of delay differential equation studied in [4,9,12,23,[25][26][27] is a special case of the class nonlinear Volterra delay integro-differential equation considered in this article. Hence, our results generalize, improve and unify the corresponding results in [4,9,12,15,[23][24][25][26][27][28] and several others in the existing literature.…”