1. Clements, D., & Sarama, J. (2007a). Early childhood mathematics learning. In F. K. Lester Jr. (Ed.), Second handbook of research on mathematics teaching and learning (pp. 461–555). Charlotte, NC: Information Age Publishing.
2. Clements, D., & Sarama, J. (2007b). Effects of a preschool mathematics curriculum: Summative research on the building blocks project. Journal for Research in Mathematics Education, 38(2), 136–163.
3. Cole, M. (1996). Cultural psychology: A once and future discipline. Cambridge, MA: The Belknap Press.
4. Drijvers, P., Doorman, M., Boon, P., Reed, H., & Gravemeijer, K. (2010). The teacher and the tool: Instrumental orchestrations in the technology-rich mathematics classroom. Educational Studies in Mathematics, 75, 213–234.
5. Drijvers, P., Tacoma, S., Besamusca, A., Doorman, M., & Boon, P. (2013). Digital resources inviting changes in mid-adopting teachers’ practices and orchestrations. ZDM - The International Journal on Mathematics Education, 45(7), 981–1001. doi: 10.1007/s11858-013-0535-1