POULSEN, Ebbe Thue. On the Algebra Generated by a Continuous Function. Mathematica Scandinavica, Berkeley, CA, United States, v. 6, p. 37–39, 1958. DOI: 10.7146/math.scand.a-10533. Disponível em: https://journals.msp.org/mscand/article/view/2810. Acesso em: 25 jul. 2026.