JOHNSON, P.; KRUMPELMAN, A. On the Babai and Upper Chromatic Numbers of Graphs of Diameter 2. Tamkang Journal of Mathematics, [S. l.], v. 52, n. 1, p. 113-123, 2021. DOI: 10.5556/j.tkjm.52.2021.3430. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/3430. Acesso em: 14 apr. 2021.