BARANNYK, T. A.; BARANNYK, A. F.; YURYK, I. I. Generalized procedure of separation of variables and reduction of nonlinear wave equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 61, n. 7, p. 892–905, 2009. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3065. Acesso em: 5 dec. 2025.