HOBBS, C. A.; KIRK, N. P. On the classification and bifurcation of multigerms of maps from surfaces to 3-space. MATHEMATICA SCANDINAVICA, [S. l.], v. 89, n. 1, p. 57–96, 2001. DOI: 10.7146/math.scand.a-14331. Disponível em: https://www.mscand.dk/article/view/14331. Acesso em: 6 may. 2024.