Fradkov A., “Feedback Analysis of Nonlinear Systems”, Control of Oscillations and Chaos, Vols 1-3, Proceedings, eds. Chernousko F., Fradkov A., IEEE, 2000, 514–517
Fradkov A., “Exploring Nonlinearity by Feedback”, Physica D, 128:2-4 (1999), 159–168