BARANNYK, T. A.; BARANNYK, A. F.; YURYK, I. I. Exact solutions of the nonliear equation $u_{tt} = = a(t) uu_{xx} + b(t) u_x^2 + c(t) u $. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 69, n. 9, p. 1180–1186, 2017. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1768. Acesso em: 27 apr. 2025.