TY  - JOUR
AU  - C. Leopold 
TI  - Virtual and Real Geometry Learning Environments
JO  - Journal for geometry and graphics
PY  - 2009
SP  - 121
EP  - 13
VL  - 13
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/JGG_2009_13_1_JGG_2009_13_1_a10/
ID  - JGG_2009_13_1_JGG_2009_13_1_a10
ER  -