@article{1183421989,
author = {Lefschetz, S.},
title = {Double curves of surfaces projected from space of four dimensions},
journal = {Bull. Amer. Math. Soc.},
volume = {19},
number = {3},
year = {1912},
pages = { 70-74},
language = {en},
url = {http://dml.mathdoc.fr/item/1183421989}
}
Lefschetz, S. Double curves of surfaces projected from space of four dimensions. Bull. Amer. Math. Soc., Tome 19 (1912) no. 3, pp. 70-74. http://gdmltest.u-ga.fr/item/1183421989/