Saprikin, S.M. (2002) “Generalized invertible selfadjoint solutions of Kalman-Yakubovich-Popov inequality and Riccati inequality, with finite negative spectrum”, Methods of Functional Analysis and Topology, 8(3), pp. 72–84. Available at: https://zen.imath.kiev.ua/index.php/mfat/article/view/194 (Accessed: 17 December 2025).