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://tidsskrift.dk/math/article/view/11508. Acesso em: 14 aug. 2026.