Zhang , Jing and Rui , Hongxing. (2022). Numerical Analysis of Two-Grid Block-Centered Finite Difference Method for Two-Phase Flow in Porous Medium.
            <i>Advances in Applied Mathematics and Mechanics</i>. <i>14</i> (6).
            1433-1455.
         doi:10.4208/aamm.OA-2021-0187