IBRAHIM, R.; DARUS, M. On operator defined by double Zeta functions. Tamkang Journal of Mathematics, [S. l.], v. 42, n. 2, p. 163–174, 2010. DOI: 10.5556/j.tkjm.42.2011.645. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/645. Acesso em: 31 jul. 2025.