HSIANG, Fu Cheng. On Some Extensions of Theorems of Fejér. Mathematica Scandinavica, Berkeley, CA, United States, v. 7, p. 333–336, 1959. DOI: 10.7146/math.scand.a-10578. Disponível em: https://journals.msp.org/mscand/article/view/2768. Acesso em: 8 sep. 2026.