DIRAC, G. A. On Complete Graphs and Complete Stars Contained as Subgraphs in Graphs. Mathematica Scandinavica, Berkeley, CA, United States, v. 12, p. 39–46, 1963. DOI: 10.7146/math.scand.a-10671. Disponível em: https://journals.msp.org/mscand/article/view/2653. Acesso em: 25 jul. 2026.