The Homepage of Ernst von Glasersfeld

67Glasersfeld E. von (1981) The concepts of adaptation and viability in a constructivist theory of knowledge [pdf]. In: Sigel I. E., Brodzinsky D. M. & Golinkoff R. M. (eds.) Piagetian theory and research. Hillsdale N. J.: Erlbaum, 87–95. Available at http://vonglasersfeld.com/067
67.1German translation: Chapter 13 in 108 (1987).