“Existence of Solutions and Hyers-Ulam Stability for a Coupled System of Nonlinear Langevin Equations Involving φ-Riemann-Liouville and ψ-Caputo Fractional Derivatives Subject to Mixed Boundary Conditions”. Gulf Journal of Mathematics, vol. 20, no. 2, Aug. 2025, pp. 489-08, https://doi.org/10.56947/gjom.v20i2.3279.