Chaiklin, S. (2003). The zone of proximal development in Vygotsky's analysis of learning and instruction. In Kozulin, A., Gindis, B., Ageyev, V., & Miller, S. (Eds.), Vygotsky's educational theory in cultural context (pp. 339–364). Cambridge, UK: Cambridge University Press.
Edwards, A. (2010). Being an expert professional practitioner: The relational turn in expertise. Dordrecht Heidelberg: Springer.
Engeström, Y. (2014). Learning by expanding: An activity-theoretical approach to developmental research. New York: Cambridge University Press.
Fleer, (2013). Play as a cultural form of development. Cambridge, UK: Cambridge University Press.
Wartofsky, W.M. (1979). Models: Representations and scientific understandings. Dordrect: Reidel.