1. Absolute stability criterion for nonlinear control systems;Barkin;Automat. Remote Control,1981
2. Real-frequency stability criteria for linear time-varying systems;Bongiorno,1964
3. Lie algebras and Lie groups in control theory;Brockett,1973
4. Liapunov functions for the problem of Lur'e in automatic control;Kalman,1964
5. On an expanding of Popov frequency-domain criterion for nonstationary nonlinearities;Leonov;Avtom. Telemekh.,1980