“…In the last few decades, the oscillation problem of functional differential equations has received much attention from mathematicians; see, for example, . The reader is referred to [1,2,[4][5][6]9,10,12,13,17,20,22,23,26] and [1,2,7,8,11,14,15,[17][18][19]24,27,[30][31][32][34][35][36][37] for the oscillation of Equations ( 1) and (2), respectively. The results on oscillation criteria of most of these works have iterative forms.…”