@article{GDZPPN00225333X, title = {Ueber die Clifford-Klein'schen Raumformen.}, journal = {Mathematische Annalen}, volume = {38}, year = {1891}, pages = {257-278}, zbl = {23.0529.01}, url = {http://dml.mathdoc.fr/item/GDZPPN00225333X} }
Killing, W. Ueber die Clifford-Klein'schen Raumformen.. Mathematische Annalen, Tome 38 (1891) pp. 257-278. http://gdmltest.u-ga.fr/item/GDZPPN00225333X/