Spicer, J. (2000): Virtual Manipulative: A New Tool for Hands-on Math. ENC Focus 7 (4) p. 14. Extraído en junio de 2004 de Http://www.enc.org/features/focus/archive...
VanLehn, K. (1982): “Bugs are not enough: Empirical studies of bugs, impasses and repairs in procedural skills”. Journal of Mathematical Behaviour,...
VanLehn, K. (1983a): Felicity conditions for human skill acquisition: Validating an AI-based Theory (Tech. Rep. No. CIS-21). Palo...
VanLehn, K. (1983b):”On the Representation of Procedures in Repair Theory” In: Ginsburg, H. (ed.), The Development of Mathematical...
VanLehn, K. (1990): Mind bugs: origins of procedural misconceptions. Cambridge, Mass.: MIT Press.
VanLehn, K., Ohlsson, S.; Nason, R. (1994):“ Applications of Simulated Students: An Exploration”. Journal of Artificial...
Wolfram, S. (1991): “Mathematica. A System for Doing Mathematics by Computer”. Addison-Wesley.
Young, R. y O’Shea, T. (1981):” Errors in children’s subtraction”. Cognitive Science, 5, 153-177.