BLUMENTHAL, Robert George. Holomorphically Closed Algebras of Analytic Functions. MATHEMATICA SCANDINAVICA, [S. l.], v. 34, p. 84–90, 1974. DOI: 10.7146/math.scand.a-11508. Disponível em: https://www.mscand.dk/article/view/11508. Acesso em: 5 dec. 2025.