KORZYUK, V.; RUDZKO, J. V. Curvilinear Parallelogram Identity and Mean-Value Property for a Semilinear Hyperbolic Equation of the Second Order. Eurasian Mathematical Journal, [S. l.], v. 15, n. 2, p. 61–74, 2024. DOI: 10.32523/2077-9879-2024-15-2-61-74. Disponível em: https://emj.enu.kz/index.php/main/article/view/343. Acesso em: 11 sep. 2026.