KRISTENSEN, Leif; MADSEN, Ib. Note on Whitehead Products in Spheres. MATHEMATICA SCANDINAVICA, [S. l.], v. 21, p. 301–314, 1967. DOI: 10.7146/math.scand.a-10865. Disponível em: https://www.mscand.dk/article/view/10865. Acesso em: 15 feb. 2026.