SAPIO, Rodolfo De. On $(k-1)$-Connected $(2k+1)$-Manifolds. Mathematica Scandinavica, Berkeley, CA, United States, v. 25, p. 181–189, 1969. DOI: 10.7146/math.scand.a-10955. Disponível em: https://journals.msp.org/mscand/article/view/2391. Acesso em: 25 jul. 2026.