BEURLING, A. A theorem on functions defined on a semi-group. MATHEMATICA SCANDINAVICA, [S. l.], v. 1, p. 127–130, 1953. DOI: 10.7146/math.scand.a-10372. Disponível em: https://www.mscand.dk/article/view/10372. Acesso em: 24 nov. 2024.