@article{GDZPPN002110776,
title = {On the geometric rank of homogeneous spaces of nonpositive curvature.},
journal = {Inventiones mathematicae},
volume = {114},
year = {1993},
pages = {151-170},
zbl = {0792.53048},
url = {http://dml.mathdoc.fr/item/GDZPPN002110776}
}
Heber, Jens. On the geometric rank of homogeneous spaces of nonpositive curvature.. Inventiones mathematicae, Tome 114 (1993) pp. 151-170. http://gdmltest.u-ga.fr/item/GDZPPN002110776/