PUPYREV, Sergey. Improved Bounds for Track Numbers of Planar Graphs. Journal of Graph Algorithms and Applications, [S. l.], v. 24, n. 3, p. 323–341, 2020. DOI: 10.7155/jgaa.00536. Disponível em: https://jgaa.info/index.php/jgaa/article/view/paper536. Acesso em: 30 jun. 2024.