1. Ferraris M. -Francaviglia M,On the Global Structure of Lagrangian and Hamiltonian Formalism in Higher Order Calculus of Variations, Proceedings of the Meeting «Geometry and Physics», Florence, October 12–15, 1982.
2. Garcia P. L.,The Poincaré-Cartan Invariant in the Calculus of Variations, Symposia Mathematica,14 (1974), pp. 219–246.
3. Goldschmidt H. -Sternberg S.,The Hamiltonian-Cartan formalism in the calculus of variations, Ann. Inst. Fourier, Grenoble,23 (1) (1973), pp. 203–267.
4. Hermann R.,Geometry, Physics and Systems, M. Dekker, Inc., New York (1973).
5. Krupka D.,Some geometric aspects of variational problems in fibered manifolds, Folia Fac. Scie. Nat. Univ. Purkyniane Brunensis,14, Opus 10 (1973), pp. 1–65.