Ashkan Rahimi Shirazi, Mehdi Madandoust. “Tolerant Evaluation of Different Cultivars of Sunflower (Helianthus Annus L.) Against Drought Stress”. International Journal of Modern Agriculture, vol. 10, no. 3, Nov. 2021, pp. 183 -88, http://modern-journals.com/index.php/ijma/article/view/1529.