Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{MAN_1939__116_160001, author = {J. Lense}, title = {\"Uber isotrope {Mannigfaltigkeiten}}, journal = {Mathematische Annalen}, pages = {297--309}, publisher = {mathdoc}, volume = {116}, year = {1939}, zbl = {65.0757.01}, url = {http://geodesic.mathdoc.fr/item/MAN_1939__116_160001/} }
J. Lense. Über isotrope Mannigfaltigkeiten. Mathematische Annalen, Tome 116 (1939), pp. 297-309. http://geodesic.mathdoc.fr/item/MAN_1939__116_160001/