“…It is well known that, (usually mild) solutions to nonautonomous evolution differential equations satisfy a concrete integral equation in which the integral kernels are expressed using two parameter evolution families {U (t, s)} t≥s≥0 , see [36]. Thanks to the bi-almost automorhy of the evolution operator {U (t, s)} t≥s≥0 we may prove the existence of almost automorphic solutions, see [9,10,11,17,46] for more details.…”