ET. AL., Asst.Prof.Dr.Lieth A. Majed,. Types of Filter and Ultra-filter with applications. Turkish Journal of Computer and Mathematics Education (TURCOMAT), [S. l.], v. 12, n. 11, p. 4373–4377, 2021. DOI: 10.17762/turcomat.v12i11.6569. Disponível em: https://turcomat.org/index.php/turkbilmat/article/view/6569. Acesso em: 13 oct. 2025.