A Fast Direct Solver for a Class of 3-D Elliptic Partial Differential Equation with Variable Coefficient. Communications in Computational Physics, [S. l.], v. 12, n. 4, p. 1148–1162, 2012. DOI: 10.4208/cicp.101110.061211a. Disponível em: https://global-sci.com/index.php/cicp/article/view/5999. Acesso em: 6 dec. 2025.