@article{GDZPPN002409933,
title = {Weak Holonomy Groups.},
journal = {Mathematische Zeitschrift},
volume = {121},
year = {1971},
pages = {290-300},
zbl = {0222.53043},
url = {http://dml.mathdoc.fr/item/GDZPPN002409933}
}
Gray, Alfred. Weak Holonomy Groups.. Mathematische Zeitschrift, Tome 121 (1971) pp. 290-300. http://gdmltest.u-ga.fr/item/GDZPPN002409933/