EXOO, G.; HARARY, F.; KABELL, J. The crossing numbers of some generalized Petersen graphs. MATHEMATICA SCANDINAVICA, [S. l.], v. 48, p. 184–188, 1981. DOI: 10.7146/math.scand.a-11910. Disponível em: https://www.mscand.dk/article/view/11910. Acesso em: 5 may. 2024.