@article{GDZPPN002280043,
title = {\"Uber isotrope Mannigfaltigkeiten},
journal = {Mathematische Annalen},
volume = {116},
year = {1939},
pages = {297-309},
zbl = {65.0757.01},
url = {http://dml.mathdoc.fr/item/GDZPPN002280043}
}
Lense, J. Über isotrope Mannigfaltigkeiten. Mathematische Annalen, Tome 116 (1939) pp. 297-309. http://gdmltest.u-ga.fr/item/GDZPPN002280043/