SamoilenkoA. M. “Some Problems of the Linear Theory of Systems of Ordinary Differential Equations”. Ukrains’kyi Matematychnyi Zhurnal 63, no. 2 (February 25, 2011): 237-269. Accessed November 23, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2714.