The Homepage of Ernst von Glasersfeld

83Glasersfeld E. von (1983) Learning as a constructive activity [pdf]. In: Bergeron J. C. & Herscovics N. (eds.) Proceedings of the 5th Annual Meeting of the North American Group of Psychology in Mathematics Education, Vol. 1. Montreal: PME-NA, 41–101. Available at http://www.vonglasersfeld.com/083
83.1German translation: Chapter 22 in 107 (1987).