1. P.Dedecker-Calcul des Variations,Formes Differentielles et Champs Geodesiques,Colloques Internationales du CNRS, Strassbourg 1953.
2. P.Dedecker-On the generalization of symplectic geometry to multiple integrals in the calculus of variations, Lecture Notes in Mathematics 570,p.394–456.
3. H. Goldschmidt,S. Sternberg-The Hamilton-Cartan formalism in the calculus of variations,Ann.Inst.Fourier 23 1973 p.203–267.
4. S.Sternberg-Some preliminary remarks on the formal variational calculus of Gelfand and Dikki,Lecture Notes in Mathematics 670.
5. H. Weyl-Geodesic fields, Ann. of Math. 36 (1935), p.607–629.