KOPACHEVSKY, N. D.; SYOMKINA, E. V. Linear Volterra Integro-Differential Second-Order Equations Unresolved with Respect to the Highest Derivative. Eurasian Mathematical Journal, [S. l.], v. 4, n. 4, p. 64–87, 2013. Disponível em: https://emj.enu.kz/index.php/main/article/view/556. Acesso em: 3 aug. 2025.