A. HAMMODAT, A.; A. BILAL, A.; S. MOHAMMED, A. Some basic properties of idempotent matrices. Journal of Education and Science, [S. l.], v. 21, n. 4, p. 124–130, 2008. DOI: 10.33899/edusj.2008.56102. Disponível em: https://edusj.uomosul.edu.iq/index.php/edusj/article/view/42404. Acesso em: 10 sep. 2025.