@article{GDZPPN002102331,
title = {Differentiability and rigidity of M\"obius groups.},
journal = {Inventiones mathematicae},
volume = {82},
year = {1985},
pages = {557-578},
zbl = {0564.30033},
url = {http://dml.mathdoc.fr/item/GDZPPN002102331}
}
Tukia, P. Differentiability and rigidity of Möbius groups.. Inventiones mathematicae, Tome 82 (1985) pp. 557-578. http://gdmltest.u-ga.fr/item/GDZPPN002102331/