JASSIM, Sahib K.; ABDULNABY, Zainab I. Statistical Approximation Operators. Ibn AL-Haitham Journal For Pure and Applied Sciences, Baghdad, Iraq., v. 26, n. 3, p. 350–356, 2017. Disponível em: https://jih.uobaghdad.edu.iq/index.php/j/article/view/446. Acesso em: 29 mar. 2025.