A. M. Al-Doori, Saad. 2014. “Effect of Different Levels and Timing of Zinc Foliar Application on Growth, Yield and Quality of Sunflower Genotypes (Helianthus Annuus L., Compositae”. College of Basic Education Research Journal 13 (1):907-22. https://jeh.uomosul.edu.iq/index.php/berj/article/view/39527.