Feedback in state constrained optimal control

Clarke, Francis H.; Rifford, Ludovic; Stern, R. J.

ESAIM: Control, Optimisation and Calculus of Variations, Volume 7 (2002) p. 97-133

On the existence of nonsmooth control-Lyapunov functions in the sense of generalized gradients

Rifford, Ludovic

ESAIM: Control, Optimisation and Calculus of Variations, Volume 6 (2001) p. 593-611