Horban’, N. V., and A. N. Stanzhitskii. “Global Attractor for the Autonomous Wave Equation in Rn With Continuous Nonlinearity”. Ukrains’kyi Matematychnyi Zhurnal 60, no. 2 (February 25, 2008): 260–267. Accessed April 7, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/3154.