DIDIMO, Walter; GIORDANO, Francesco; LIOTTA, Giuseppe. Overlapping Cluster Planarity. Journal of Graph Algorithms and Applications, [S. l.], v. 12, n. 3, p. 267–291, 2008. DOI: 10.7155/jgaa.00167. Disponível em: https://jgaa.info/index.php/jgaa/article/view/paper167. Acesso em: 30 jun. 2024.