%0 Journal Article
%A C. Leopold 
%T Virtual and Real Geometry Learning Environments
%J Journal for geometry and graphics
%D 2009
%P 121-13
%V 13
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/JGG_2009_13_1_JGG_2009_13_1_a10/
%F JGG_2009_13_1_JGG_2009_13_1_a10