@article{1183539469,
author = {Schwarz, Gerald W.},
title = {Covering smooth homotopies of orbit spaces},
journal = {Bull. Amer. Math. Soc.},
volume = {83},
number = {6},
year = {1977},
pages = { 1028-1030},
language = {en},
url = {http://dml.mathdoc.fr/item/1183539469}
}
Schwarz, Gerald W. Covering smooth homotopies of orbit spaces. Bull. Amer. Math. Soc., Tome 83 (1977) no. 6, pp. 1028-1030. http://gdmltest.u-ga.fr/item/1183539469/