Abbas, A., 		Hamad, M., 		Babiker, H., & 		Nour, A.
(2007).
 Effects of phosphorus and zinc fertilizers on their    contents in soil, plant and grains of corn.
<em>Gezira Journal Of Agricultural Science, 5</em>(2).
Retrieved from <a href="http://37.60.236.48/index.php/gjas/article/view/444" target="_new">http://37.60.236.48/index.php/gjas/article/view/444</a>