YUSUBOV, Sh. Sh. Nonlocal problem with integral conditions for a high-order hyperbolic equation. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 69, n. 1, p. 121–131, 2017. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1681. Acesso em: 6 dec. 2025.