Two $P_4$ Nonconforming Finite Elements for the Biharmonic Equation on Rectangular Meshes. Advances in Applied Mathematics and Mechanics, [S. l.], v. 18, n. 4, p. 1142–1154, 2026. DOI: 10.4208/aamm.OA-2025-0165. Disponível em: https://www.global-sci.com/aamm/article/view/23445. Acesso em: 18 apr. 2026.