%0 Journal Article %A R. Kaufman %T Perfect sets in some groups %J Studia Mathematica %D 1970 %P 17-21 %V 34 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/sm-34-1-17-21/ %R 10.4064/sm-34-1-17-21 %G en %F 10_4064_sm_34_1_17_21