[1] M. Doupovec: Natural operators transforming vector fields to the second order tangent bundle. Čas. pěst. mat. 115 (1990), 64–72. MR 1044015 | Zbl 0712.58003

[2] M. Doupovec: Natural transformations between $T^2_1T^*M$ and $T^*T^2_1M$. Ann. Polon. Math. 56 (1991), 67–77. DOI 10.4064/ap-56-1-67-77 | MR 1145571 | Zbl 0743.53016

[3] G. Kainz, P.W. Michor: Natural transformations in differential geometry. Czech. Math. J. 37 (1987), 584–607. MR 0913992

[4] P. Kobak: Natural liftings of vector fields to tangent bundles of bundles of 1-forms. Mathematica Bohemica 116 (1991), 319–326. MR 1126453 | Zbl 0743.53008

[5] I. Kolář: Natural transformations of the second tangent functor into itself. Arch. Math.(Brno) XX (1984), 169–172. MR 0784868

[6] I. Kolář: On the natural operators on vector fields. Ann. Global Anal. Geom. 6 (1988), 109–117. DOI 10.1007/BF00133034 | MR 0982760

[7] I. Kolář, Z. Radziszewski: Natural transformations of second tangent and cotangent functors. Czech. Math. J. 38(113) (1988), 274–279. MR 0946296

[8] I. Kolář, M. Modugno: Torsions of connections on some natural bundles. Differential Geometry and its Applications 2 (1992), 1–16. MR 1244453

[9] I. Kolář, P.W. Michor, J. Slovák: Natural operations in differential geometry. Springer Verlag, 1993. MR 1202431

[10] M. Modugno, G. Stefani: Some results on second tangent and cotangent spaces. Quaderni dell’ Instituto di Matematica dell’ Universita di Lecce Q.16 (1978).

[11] A. Nijenhuis: Natural bundles and their general properties. Diff. Geometry in honor of K. Yano, Kinokuniya,Tokyo (1972), 317–334. MR 0380862 | Zbl 0246.53018

[12] J. E. White: The method of iterated tangents with applications in local Riemannian geometry. Pitman Press, London, 1982. MR 0693620 | Zbl 0478.58002