DERRY, Douglas. On Polygons in Real Projective $n$-Space. Mathematica Scandinavica, Berkeley, CA, United States, v. 6, p. 50–66, 1958. DOI: 10.7146/math.scand.a-10536. Disponível em: https://journals.msp.org/mscand/article/view/2811. Acesso em: 25 jul. 2026.