DUPONT, J. L. On Homotopy Invariance of the Tangent Bundle II. MATHEMATICA SCANDINAVICA, [S. l.], v. 26, p. 200–220, 1970. DOI: 10.7146/math.scand.a-10977. Disponível em: https://www.mscand.dk/article/view/10977. Acesso em: 3 may. 2024.