@article{701490,
     title = {Higher order geodesic symmetries},
     booktitle = {Proceedings of the Winter School "Geometry and Physics"},
     series = {GDML\_Books},
     publisher = {Circolo Matematico di Palermo},
     address = {Palermo},
     year = {1991},
     pages = {[163]-170},
     mrnumber = {MR1151902},
     zbl = {0748.53031},
     url = {http://dml.mathdoc.fr/item/701490}
}

García, A.; Jiménez, J. A.; Sánchez, C. U. Higher order geodesic symmetries, dans Proceedings of the Winter School "Geometry and Physics", GDML_Books,  (1991), pp. [163]-170. http://gdmltest.u-ga.fr/item/701490/