@article{MAN_1927__97_182639,
     author = {T. Levi-Civita},
     title = {Sur l'\'ecart g\'eod\'esique},
     journal = {Mathematische Annalen},
     pages = {291--320},
     publisher = {mathdoc},
     volume = {97},
     year = {1927},
     zbl = {52.0740.01},
     url = {http://geodesic.mathdoc.fr/item/MAN_1927__97_182639/}
}