4Von Glasersfeld. E, Questions and answers about radical constructivism[A]. K. Tobin (ed,). The practice of Constructivismin Science Education[C]. Washington DC : AAAS press, 1993.
5Von Glasersfeld. E. Constructivism Revisited: A Reply to Such tingEA3. M. R. Matthens. Constructivism in Science Education[C]. Kluwer Academic Publishers, 1998,97.