2021. A Two-Level Factored Crank-Nicolson Method for Two-Dimensional Nonstationary Advection-Diffusion Equation with Time Dependent Dispersion Coefficients and Source Terms. Advances in Applied Mathematics and Mechanics. 13, 5 (June 2021), 1005–1026. DOI:https://doi.org/10.4208/aamm.OA-2020-0206.