MAHMMOD MOHAMMED ALI, N. Commercial Structure in 17-30 Quarter. College of Basic Education Research Journal, [S. l.], v. 6, n. 2, p. 399–425, 2007. Disponível em: https://stats.uomosul.edu.iq/index.php/berj/article/view/38172. Acesso em: 26 oct. 2025.