عبدالله, موسي يوسف et al. Gezira Student Net Work Organization. Gezira Journal of Health Sciences, [S.l.], v. 1, n. 2, jan. 2005. ISSN 1810-5386. Available at: <http://journals.uofg.edu.sd/index.php/gjhs/article/view/201>. Date accessed: 20 oct. 2019.