@article{GDZPPN002057077,
title = {On the existence of a connection with curvature zero.},
journal = {Commentarii mathematici Helvetici},
volume = {32},
year = {1957},
pages = {215-223},
zbl = {0196.25101},
url = {http://dml.mathdoc.fr/item/GDZPPN002057077}
}
Milnor, John. On the existence of a connection with curvature zero.. Commentarii mathematici Helvetici, Tome 32 (1957) pp. 215-223. http://gdmltest.u-ga.fr/item/GDZPPN002057077/