HERRMANN, C. Unikales Mathematik-Schulbuch aus dem Südwesten. WLBforum, Stuttgart, v. 19, n. 1, p. 45–46, 2017. DOI: 10.53458/wlbf.v19i1.203. Disponível em: https://journals.wlb-stuttgart.de/ojs/index.php/wlbf/article/view/203. Acesso em: 22 mai. 2022.