[1] A. Dekrét: Mechanical structures and connection. to appear. MR 1040061

[2] J. Janyška: Geometric properties of prolongation functors. Časopis pӗst. mat. 110, (1985), 77-86. MR 0791280

[3] J. Klein: Geometry of sprays. IUТАM-ISIMM Symposium on analytical mechanics, Тorino, 1982, 177-196. MR 0773487

[4] I. Kolář: Some natural operators in differential geometгy. Proc. Сonf. on Diff. Geometry and Аpplications in Brno, D. Reidel Publ. Сompany, (1986), 91-110. MR 0923346

[5] D. Krupka: Elementary theory of differential invariants. Аrch. Math. (Brno) 14 (1978), 207-214. MR 0512763 | Zbl 0428.58002

[6] P. Libermann M. Marle: Symplectic Geometry and Аnalytical Mechanics. D. Riedel Publ. Сompany, (1987).

[7] A. Nijenluris: Natural bundles and their general properties. Diff. Geometry in honour of K. Yano, Kinokuniya, Тokio, (1972), 317-334.

[8] M. Crampin: Аlternative Lagrangians in particle dynamics. Proc. Сonf. on Diff. Geometry and Аpplications in Brno, D. Reidel Publ. Сompany, (1986), 1-12. MR 0923340