@article{bwmeta1.element.desklight-9c14f531-ee33-4b3d-9539-de352d5e2712,
author = {Udo Simon},
title = {On differential operators of second order on Riemannian manifolds with nonpositive curvature},
journal = {Colloquium Mathematicae},
volume = {31},
year = {1974},
pages = {223-229},
zbl = {0263.53035},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.desklight-9c14f531-ee33-4b3d-9539-de352d5e2712}
}
Udo Simon. On differential operators of second order on Riemannian manifolds with nonpositive curvature. Colloquium Mathematicae, Tome 31 (1974) pp. 223-229. http://gdmltest.u-ga.fr/item/bwmeta1.element.desklight-9c14f531-ee33-4b3d-9539-de352d5e2712/