“…According to Krasnoselskii's fixed point theorem, some new results are presented. However, considering the cases such as g(t) = t -2, g(t) = t/3, and g(t) = t + cos t for t ∈ [t 0 , ∞) T , the conclusions in [24] are not applicable when g(t) ≥ t is not fulfilled eventually, especially for [7,8,[15][16][17][18][19][20][21][22]. Afterwards, Qiu et al [25] studied (2) under g(t) ≤ t for t ∈ [t 0 , ∞) T and partially solved the problem.…”