%0 Journal Article
%A Timo Erkama
%T Group actions and extension problems for maps of balls
%J Annales Fennici Mathematici
%D 1973
%V 521-560
%I mathdoc
%U http://geodesic.mathdoc.fr/articles/10.5186/aasfm.1973.556/
%R 10.5186/aasfm.1973.556
%G en
%F AFM_1973_521-560_a4