BoichukО. A., and KrivosheyaS. A. “Criterion of the Solvability of Matrix Equations of the Lyapunov Type”. Ukrains’kyi Matematychnyi Zhurnal 50, no. 8 (August 25, 1998): 1021–1026. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/4851.