The Convergence of Multigrid Methods for Solving Finite Element Equations in the Presence of Singularities. Journal of Computational Mathematics, [S. l.], v. 13, n. 4, p. 315–324, 2021. Disponível em: https://staging.gsp.tricubic.dev/JCM/article/view/11186. Acesso em: 18 mar. 2026.