4Jonassen D H. What is cognitive tools? [A]. In:Kommers P,Jonssen D,Mayes J, eds. Cognitive Tools for Learning[M].Berlin : Springer- Verlag Publications, 1992.
5Jonassen D H. Objectivism versus constructivism: Do we need a new philosophical paradigm? [J]. ETR&D, 39(3), 5-14,1991.