Zhumatov, S. S. “On the Stability of a Program Manifold of Control Systems With Variable Coefficients”. Ukrains’kyi Matematychnyi Zhurnal 71, no. 8 (August 25, 2019): 1053–1063. Accessed December 5, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/1497.