AUBERT, K. E. Convex Ideals in Ordered Group Algebras and the Uniqueness of the Haar Measure. Mathematica Scandinavica, Berkeley, CA, United States, v. 6, p. 181–188, 1958. DOI: 10.7146/math.scand.a-10542. Disponível em: https://journals.msp.org/mscand/article/view/2799. Acesso em: 8 sep. 2026.