KOVALEVSKY , A. A. Convergence of solutions of variation inequalities with bilateral obstacles in perforated regions. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 44, n. 2, p. 191–197, 1992. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/7832. Acesso em: 6 dec. 2025.