@article{GDZPPN002090880, title = {Group Actions and Curvature.}, journal = {Inventiones mathematicae}, volume = {27}, year = {1974}, pages = {31-48}, zbl = {0271.53044}, url = {http://dml.mathdoc.fr/item/GDZPPN002090880} }
Grove, K.; Karcher, H.; Ruh, E.A. Group Actions and Curvature.. Inventiones mathematicae, Tome 27 (1974) pp. 31-48. http://gdmltest.u-ga.fr/item/GDZPPN002090880/