Existence of differentiable structure in the set of submanifolds. An attempt of geometrization of calculus of variations Jerzy Kijowski — 1969 Studia Mathematica
On representation of functionals of local type by differential forms Jerzy Kijowski — 1972 Colloquium Mathematicae
STANISŁAW ZAKRZEWSKI (28.6.1951-30.4.1998) Jerzy Kijowski; Paweł Urbański; Stanisław Woronowicz — 2000 Banach Center Publications