Hrod, I. M. “Conditions for the Existence of Bounded Solutions of One Class of Nonlinear Differential Equations”. Ukrains’kyi Matematychnyi Zhurnal 58, no. 3 (March 25, 2006): 317–325. Accessed April 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3456.