@article{BSMF_1931__59__70_0,
     author = {Bortolotti, Enea},
     title = {Directions concourantes et connexions dans les espaces courbes},
     journal = {Bulletin de la Soci\'et\'e Math\'ematique de France},
     pages = {70--74},
     publisher = {Soci\'et\'e math\'ematique de France},
     volume = {59},
     year = {1931},
     doi = {10.24033/bsmf.1173},
     zbl = {0002.15701},
     language = {fr},
     url = {http://archive.numdam.org/articles/10.24033/bsmf.1173/}
}