INGELSTAM, L. A Vertex Property for Banach Algebras with Identity. MATHEMATICA SCANDINAVICA, [S. l.], v. 11, p. 22–32, 1962. DOI: 10.7146/math.scand.a-10646. Disponível em: https://www.mscand.dk/article/view/10646. Acesso em: 27 apr. 2024.