TSYLIN, I. V. On Relationship Between the Resolvent Convergence and the Smoothness of Solutions to Boundary Value Problems. Eurasian Mathematical Journal, [S. l.], v. 7, n. 3, p. 100–103, 2016. Disponível em: https://emj.enu.kz/index.php/main/article/view/645. Acesso em: 3 jan. 2026.