KERANTO, Tapio. A problem-centered alternative to formalistic teaching. NOMAD Nordic Studies in Mathematics Education, [S. l.], v. 2, n. 2, p. 36–57, 1994. DOI: 10.7146/nomad.v2i2.146105. Disponível em: https://tidsskrift.dk/NOMAD/article/view/146105. Acesso em: 10 dec. 2025.