Ghandor, Wadii, et al. “Controllability of Fractional Differential Systems With State and Control Delay by Using Riemann--Liouville Fractional Derivatives”. Discontinuity, Nonlinearity, and Complexity, vol. 15, no. 3, Aug. 2026, pp. 381-94, https://doi.org/10.5890/DNC.2026.09.007.