MANDACHE, N. On a counterexample concerning unique continuation for elliptic equations in divergence form. Математическая физика, анализ, геометрия, Харків, Україна, v. 3, n. 3-4, p. 308–331, 1996. Disponível em: https://mag.ilt.kharkiv.ua/index.php/mag/article/view/m03-0308e. Acesso em: 4 груд. 2024.