Numerical solution of fractional advection-diffusion equation with generalized Caputo derivative using shifted ultraspherical collocation method. J. Nig. Soc. Phys. Sci. [Internet]. 2026 [cited 2026 Oct. 16];8(2):2986. Available from: https://journal.nsps.org.ng/index.php/jnsps/article/view/2986