Barannyk, T. A., A. F. Barannyk, and I. I. Yuryk. “Exact Solutions of the Nonliear Equation $u_{tt} = = a(t) uu_{xx} + b(t) u_x^2 + c(t) U $”. Ukrains’kyi Matematychnyi Zhurnal 69, no. 9 (September 25, 2017): 1180-1186. Accessed April 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/1768.