BOGOLYUBOV, A.; PANIN, A. An error estimate for approximate solutions to elliptic equations with non-coercive bilinear form. Numerical Methods and Programming (Vychislitel’nye Metody i Programmirovanie), [S. l.], v. 10, n. 19, p. 34–48, 2008. Disponível em: https://en.num-meth.ru/index.php/journal/article/view/345. Acesso em: 25 apr. 2024.