Reichenberg, Olof. “Explaining Variation in Usage of Instructional Material in Teaching Practice: Collegial Focus and teachers’ Decision-Making Power”. IARTEM e-journal 7, no. 2 (September 9, 2015): 22–47. Accessed April 19, 2026. https://mail.iartemejournal.org/index.php/IARTEM/article/view/745.