EL BASHEER, E. S. A.; HASSAN MOHAMED, Z. I. The sources of Economic Financial Value from Black Sand. مجلة البطانة للعلوم التطبيقية, [S. l.], n. 12, p. 42–46, 2022. Disponível em: https://ojs.albutana.edu.sd/index.php/jas/article/view/162. Acesso em: 20 2024.