@article{05345494,
title = {Curvature in synthetic differential geometry of groupoids.},
journal = {Beitr\"age zur Algebra und Geometrie},
volume = {49},
year = {2008},
pages = {369-381},
zbl = {1160.51012},
language = {en},
url = {http://dml.mathdoc.fr/item/05345494}
}
Nishimura, Hirokazu. Curvature in synthetic differential geometry of groupoids.. Beiträge zur Algebra und Geometrie, Tome 49 (2008) pp. 369-381. http://gdmltest.u-ga.fr/item/05345494/