EPPSTEIN, David. Edge Bounds and Degeneracy of Triangle-Free Penny Graphs and Squaregraphs. Journal of Graph Algorithms and Applications, [S. l.], v. 22, n. 3, p. 483–499, 2018. DOI: 10.7155/jgaa.00463. Disponível em: https://jgaa.info/index.php/jgaa/article/view/paper463. Acesso em: 1 jul. 2024.