GANELIUS, T. On one-sided approximation by trigonometrical polynomials. MATHEMATICA SCANDINAVICA, [S. l.], v. 4, p. 247–258, 1956. DOI: 10.7146/math.scand.a-10473. Disponível em: https://www.mscand.dk/article/view/10473. Acesso em: 11 apr. 2025.