“…In relation to the Carleman estimates for the parabolic integro-differential equations, we refer to works by A. Lorenzi et al [25,26,27,28,29,30]. In their article, they treat the case of that the integrands of the Volterra type integral in the equations are the first or zero-th order in space, that is, the case of a ij = 0 for i, j = 1, .…”