@article{02186441,
title = {Lifting smooth homotopies of orbit spaces of proper Lie group actions.},
journal = {Journal of Lie Theory},
volume = {15},
year = {2005},
pages = {447-456},
zbl = {1079.57025},
language = {en},
url = {http://dml.mathdoc.fr/item/02186441}
}
Kankaanrinta, Marja. Lifting smooth homotopies of orbit spaces of proper Lie group actions.. Journal of Lie Theory, Tome 15 (2005) pp. 447-456. http://gdmltest.u-ga.fr/item/02186441/