DUPONT, Johan L. Symplectic Bundles and $KR$-Theory. Mathematica Scandinavica, Berkeley, CA, United States, v. 24, p. 27–30, 1969. DOI: 10.7146/math.scand.a-10918. Disponível em: https://journals.msp.org/mscand/article/view/2380. Acesso em: 25 jul. 2026.