“On the Convergence of Nonconforming Finite Element Methods for the 2nd Order Elliptic Problem with the Lowest Regularity”, JCM, vol. 17, no. 6, pp. 609–614, July 2021, Accessed: Mar. 15, 2026. [Online]. Available: https://gsp.tricubic.dev/JCM/article/view/11346