On Approximation of Laplacian Eigenproblem over a Regular Hexagon with Zero Boundary Conditions. Journal of Computational Mathematics, [S. l.], v. 22, n. 2, p. 275–286, 2004. Disponível em: https://www.global-sci.com/index.php/JCM/article/view/11629. Acesso em: 5 dec. 2025.