@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/