D. A. Vianny, R. Dhineshbabu, and A. G. M. Selvam, “LYAPUNOV TYPE INEQUALITIES AND THEIR APPLICATIONS ON AN EIGENVALUE PROBLEM FOR DISCRETE FRACTIONAL ORDER EQUATION WITH A CLASS OF BOUNDARY CONDITIONS”, Adv. Differ. Equ. Control Process., vol. 28, pp. 55–71, Jun. 2022.