Mayi, A. A., and G. M. A. Saeed. “Effect of Foliar Spray of Kno3, Humic Acid Cultivars and Their Interactions on Leaf Nutrients of Olive (olea Europaea l.) Cvs. Khithary and i18 Transplants”. Science Journal of University of Zakho, vol. 3, no. 1, June 2015, pp. 88-96, https://sjuoz.uoz.edu.krd/index.php/sjuoz/article/view/103.