SIGLER, A.; STUPEL, M. Proof Without Words. Ohio Journal of School Mathematics, [S. l.], v. 74, n. 2, 2017. Disponível em: https://www.osu.tests.sfulib4.publicknowledgeproject.org/index.php/OJSM/article/view/5616. Acesso em: 29 apr. 2026.