WAHDE, G. An Extremal Problem Related to the Theory of Quasi-Analytic Functions. MATHEMATICA SCANDINAVICA, [S. l.], v. 7, p. 126–132, 1959. DOI: 10.7146/math.scand.a-10566. Disponível em: https://www.mscand.dk/article/view/10566. Acesso em: 3 may. 2024.