HELSON, H.; BEURLING, A. Fourier-Stieltjes transforms with bounded powers. MATHEMATICA SCANDINAVICA, [S. l.], v. 1, p. 120–126, 1953. DOI: 10.7146/math.scand.a-10371. Disponível em: https://www.mscand.dk/article/view/10371. Acesso em: 2 may. 2024.