“Effect of Interaction Betw·een Phosphorus and Zink in Some Morphological Features of Two Varieties of Wheat Grown in Gypsum Soil”. Ibn AL-Haitham Journal For Pure and Applied Sciences, vol. 21, no. 3, Sept. 2017, pp. 37-55, https://jih.uobaghdad.edu.iq/index.php/j/article/view/1403.