@article{CMUC_2006__47_4_a15,
     author = {Kol\'a\v{r}, Ivan and Cabras, Antonella},
     title = {On the functorial prolongations of principal bundles},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {719--731},
     publisher = {mathdoc},
     volume = {47},
     number = {4},
     year = {2006},
     mrnumber = {2337425},
     zbl = {1150.58002},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_2006__47_4_a15/}
}