Karthikeyan, P. et al. 2026. Compactness Results on Integro-Differential Equations Involving $\Psi$-Hilfer Fractional Derivative. Discontinuity, Nonlinearity, and Complexity. 12, 3 (Aug. 2026), 631–642. DOI:https://doi.org/10.5890/DNC.2023.09.010.