GONÇALVES, Daciberg L.; SPREAFICO, Mauro. The fundamental group of the space of maps from a surface into the projective plane. MATHEMATICA SCANDINAVICA, [S. l.], v. 104, n. 2, p. 161–181, 2009. DOI: 10.7146/math.scand.a-15092. Disponível em: https://tidsskrift.dk/math/article/view/15092. Acesso em: 14 aug. 2026.