GARTSIDE, P. Proofs Without Words (Series 1). Pittsburgh Interdisciplinary Mathematics Review, Pittsburgh, v. 1, p. 143, 2024. DOI: 10.5195/pimr.2024.27. Disponível em: https://pimr.pitt.edu/pimr/article/view/27. Acesso em: 18 jan. 2025.