AMEER MAHRAN, Hatim.
 The potency of horizontal and vertical expansion on food output growth in Sudan: A causality analysis, 1962-2000.
<strong>Gezira Journal of Agricultural Science</strong>, [S.l.], v. 1, n. 2, p. 1-14, june 2021.
ISSN 1728-9556. Available at: &lt;<a href="http://37.60.236.48/index.php/gjas/article/view/1976" target="_new">http://37.60.236.48/index.php/gjas/article/view/1976</a>&gt;. Date accessed: 03 june 2026.