Necessary conditions for discrete dynamical systems with delays and general constraints Jaroslav Doležal (1981) Kybernetika
Necessary conditions for Lipschitz continuous discrete control problems Jaroslav Doležal (1985) Banach Center Publications
Necessary Conditions for Multiple Integral Problem in the Calculus of Variations. Viorel Barbu (1982) Mathematische Annalen
Necessary optimality conditions for a model of optimal control processes Leonhard Bittner (1976) Banach Center Publications
Necessary optimality conditions for discrete systems with state-dependent control region Jaroslav Doležal (1975) Kybernetika