“…On the other hand, thanks to the fact that a large number of practical and real world phenomena in the elds of biology, physics, chemistry, and computer network, can be modeled by coupled systems of di erent types of fractional di erential equations. Here, we sketch some references, but not a list of all references is included, such as Hadamard type [8], Caputo [9] and Riemann-Liouville types [10], and Ψ-Hilfer type [11].…”