“…A successful one is that based on evolution equations of fractional order and the name fractional diffusion follows. This approach has been maintained by analytical methods, e.g., [6,7,37], by random walks, e.g., [15,20,21,22], by the continuous time random walk (CTRW) through a well-scaled passage to the diffusion limit, e.g., [16,17,18,23], by the parametric subordination, e.g., [19], and by the inverse stable subordination, e.g., [1,42].…”