WINTNER, A. On an absolute constant pertaining to Cauchy’s "principal moduli" in bounded power series. MATHEMATICA SCANDINAVICA, [S. l.], v. 4, p. 108–112, 1956. DOI: 10.7146/math.scand.a-10459. Disponível em: https://www.mscand.dk/article/view/10459. Acesso em: 2 may. 2024.