%0 Journal Article
%A H.G. HELFENSTEIN
%T On the Distortion of Conformal Immersions between 2-Space Forms.
%J Mathematische Annalen
%D 1969
%P 159-168
%V 183
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MAN_1969__183_161887/
%F MAN_1969__183_161887