DUPONT, Johan L. On Homotopy Invariance of the Tangent Bundle II. Mathematica Scandinavica, Berkeley, CA, United States, v. 26, p. 200–220, 1970. DOI: 10.7146/math.scand.a-10977. Disponível em: https://journals.msp.org/mscand/article/view/2351. Acesso em: 25 jul. 2026.