EKLOF, Paul C. Homogeneous Universal Modules. Mathematica Scandinavica, Berkeley, CA, United States, v. 29, p. 187–196, 1971. DOI: 10.7146/math.scand.a-11044. Disponível em: https://journals.msp.org/mscand/article/view/2311. Acesso em: 25 jul. 2026.