Eriksson, Inger, Jenny Fred, Anna-Karin Nordin, Martin Nyman, and Sanna Wettergren. 2021. “Tasks, Tools, and Mediated Actions – Promoting Collective Theoretical Work on Algebraic Expressions”. NOMAD Nordic Studies in Mathematics Education 26 (3-4):29–52. https://tidsskrift.dk/NOMAD/article/view/149169.