[1]
S. A. . Belikov, “On observability of linear and bilinear systems of the Hilbert space”, Ukr. Mat. Zhurn., vol. 40, no. 2, pp. 139–144, Feb. 1988, Accessed: Dec. 06, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/9108