Chantal, Kwizera, Basil T. Ongor, Denis Bandushubwenge, Ndihokubwayo Soter, and Shabani Felix. 2018. “Effects of Different Nitrogen Fertilizer Levels on Sunflower Growth and Yield Attributes”. Pakistan Journal of Nutrition 17 (11): 557–562. https://doi.org/10.3923/pjn.2018.557.562.