%0 Journal Article %A P. Tukia %T Differentiability and rigidity of Möbius groups. %J Inventiones mathematicae %D 1985 %P 557-578 %V 82 %I mathdoc %U http://geodesic.mathdoc.fr/item/IM_1985__82_143300/ %F IM_1985__82_143300