Liu, Xianghu, and Yanfang Li. “The Solvability and Optimal Controls for Some Fractional Impulsive Equation With Finite Delay”. Discontinuity, Nonlinearity, and Complexity, vol. 3, no. 2, Aug. 2026, pp. 133-45, https://doi.org/10.5890/DNC.2014.06.003.