The product space approach in the state space theory of linear time-invariant differential systems with delays in state and control variables M. C. Delfour — 1985 Banach Center Publications
Analyse des problèmes de forme par la dérivation des minimax M.-C. Delfour; J.-P. Zolésio — 1989 Annales de l'I.H.P. Analyse non linéaire