@article{1077474851,
author = {Johnson, Paul B.},
title = {The role of the directrix in Levi-Civita parallelism},
journal = {Duke Math. J.},
volume = {15},
number = {1},
year = {1948},
pages = { 389-405},
language = {en},
url = {http://dml.mathdoc.fr/item/1077474851}
}
Johnson, Paul B. The role of the directrix in Levi-Civita parallelism. Duke Math. J., Tome 15 (1948) no. 1, pp. 389-405. http://gdmltest.u-ga.fr/item/1077474851/