
Michael H. G. Hoffmann
(2000-2009)
XSigns as means for discoveries
2005
in: Activity and sign, Dordrecht : Springer

Grounding mathematics education
2005
in: Activity and sign, Dordrecht : Springer

(2000-2009)
XSigns as means for discoveries
2005
in: Activity and sign, Dordrecht : Springer
Grounding mathematics education
2005
in: Activity and sign, Dordrecht : Springer