Higher order Grassmann fibrations and the calculus of variations. Krupka, D.; Krupka, M. — 2010 Balkan Journal of Geometry and its Applications (BJGA)
Finite order liftings in principal fibre bundles D. KRUPKA — 1981 Beiträge zur Algebra und Geometrie = Contributions to algebra and geometry
Comment by the editors on the paper : “The hamiltonian formalism in higher order variational problems” M. Francaviglia; D. Krupka — 1985 Annales de l'I.H.P. Physique théorique