WINTNER, Aurel. The theorem of Eneström and the extremal functions of Landau-Schur. Mathematica Scandinavica, Berkeley, CA, United States, v. 5, p. 236–240, 1957. DOI: 10.7146/math.scand.a-10500. Disponível em: https://journals.msp.org/mscand/article/view/2821. Acesso em: 25 jul. 2026.