Guan C, Niu J. A spectral operational matrix method using shifted fractional Legendre functions for nonlinear fractional Volterra integro-differential equations. MMA [Internet]. 2026 Oct. 6 [cited 2026 Oct. 9];31(4):649–670. Available from: https://journals.vilniustech.lt/index.php/MMA/article/view/24683