Ahl, Linda, Guðný Helga Gunnarsdóttir, Tuula Koljonen, and Guðbjörg Pálsdóttir. 2015. “How Teachers Interact and Use Teacher Guides in Mathematics – Cases from Sweden and Iceland”. NOMAD Nordic Studies in Mathematics Education 20 (3-4):179–197. https://doi.org/10.7146/nomad.v20i3-4.148697.