BREKKE, G.; GJONE, G. Matematikkdidaktikk. NOMAD Nordic Studies in Mathematics Education, [S. l.], v. 7, n. 3-4, p. 4–5, 1999. DOI: 10.7146/nomad.v7i3-4.146691. Disponível em: https://tidsskrift.dk/NOMAD/article/view/146691. Acesso em: 9 jan. 2025.