1. Feedback invariants for nonlinear systems;Brockett,1978
2. A classification of linear controllable systems;Brunovsky;Kibernetica cislo,1970
3. The Method of Equivalence and its Applications;Gardner,1989
4. Feedback equivalence for general control systems;Gardner;Systems Control Lett.,1990
5. Feedback equivalence and symmetries of Brunovsky normal forms;Gardner,1989