“…First-order abstract partial neutral functional differential equations have also been studied by different authors, including Adimy et al [1,2,3], Hale [11], Wu and Xia [26] and Wu [27] for finite delay, and Hernández & Henríquez [14,15] and Hernández [16] for the unbounded delay case. In addition, some abstract second-order neutral Cauchy problems have been considered recently in the literature, see for instance [5,6,7,22].…”