KRAINES, David. Twisted Multiplications on Generalized Eilenberg-Maclane Spaces. Mathematica Scandinavica, Berkeley, CA, United States, v. 32, p. 273–285, 1973. DOI: 10.7146/math.scand.a-11463. Disponível em: https://journals.msp.org/mscand/article/view/2147. Acesso em: 25 jul. 2026.