BERESNEVICH, V. V.; BERNIK, V. I.; VASYLYSHYN, P. B.; PTASHNIK, B. I. A multipoint problem with multiple nodes for linear hyperbolic equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 51, n. 10, p. 1311–1316, 1999. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4729. Acesso em: 5 dec. 2025.