ALFSEN, E. M.; FENSTAD, J. E. A Note on Completion and Compactification. Mathematica Scandinavica, Berkeley, CA, United States, v. 8, p. 97–104, 1960. DOI: 10.7146/math.scand.a-10596. Disponível em: https://journals.msp.org/mscand/article/view/2750. Acesso em: 25 jul. 2026.