@article{GDZPPN002269856,
title = {Riemann spaces conformal to Einstein spaces},
journal = {Mathematische Annalen},
volume = {92},
year = {1924},
pages = {269-278},
zbl = {50.0504.01},
url = {http://dml.mathdoc.fr/item/GDZPPN002269856}
}
Brinkmann, H.W. Riemann spaces conformal to Einstein spaces. Mathematische Annalen, Tome 92 (1924) pp. 269-278. http://gdmltest.u-ga.fr/item/GDZPPN002269856/