@article{GDZPPN002319551,
title = {Jacobi Tensors and Ricci Curvature.},
journal = {Mathematische Annalen},
volume = {250},
year = {1980},
pages = {1-26},
zbl = {0423.53035},
url = {http://dml.mathdoc.fr/item/GDZPPN002319551}
}
O'Sullivan, John J.; Eschenburg, Jost-Hinrich. Jacobi Tensors and Ricci Curvature.. Mathematische Annalen, Tome 250 (1980) pp. 1-26. http://gdmltest.u-ga.fr/item/GDZPPN002319551/