“Discrete Maximum Principle for Poisson Equation with Mixed Boundary Conditions Solved by $hp$-FEM”, Adv. Appl. Math. Mech., vol. 1, no. 2, pp. 201–214, Aug. 2018, Accessed: Mar. 15, 2026. [Online]. Available: https://gsp.tricubic.dev/aamm/article/view/4462