BINIAZ, Ahmad. A short proof of the non-biplanarity of $K_9$. Journal of Graph Algorithms and Applications, [S. l.], v. 26, n. 1, p. 75–80, 2022. DOI: 10.7155/jgaa.00582. Disponível em: https://jgaa.info/index.php/jgaa/article/view/paper582. Acesso em: 22 dec. 2024.