SHAPIRO, B. Z. On Singularities of Smooth Maps to a Space with a Fixed Cone. MATHEMATICA SCANDINAVICA, [S. l.], v. 77, p. 19–44, 1995. DOI: 10.7146/math.scand.a-12547. Disponível em: https://tidsskrift.dk/math/article/view/12547. Acesso em: 14 aug. 2026.