“…() In the case of finite history, that is, u 0 ( t ) = 0 for t < 0, see Berrimi and Messaoudi, Messaoudi, Messaoudi and Al‐Khulaifi, Muñoz Rivera et al, and Mustafa. () In particular, Rivera et al considered the interpolating cases α ∈ (0,1) and a relaxation function g , which decay exponentially to 0 at infinity, that is, …”