Guan, Chaoyue, and Jing Niu. “A Spectral Operational Matrix Method Using Shifted Fractional Legendre Functions for Nonlinear Fractional Volterra Integro-Differential Equations”. Mathematical Modelling and Analysis, vol. 31, no. 4, Oct. 2026, pp. 649–670, https://doi.org/10.3846/mma.2026.24683.