Szabó, András, and Péter Pepó. “The Effect of Plant Density on the Yield of Sunflower Hybrids in 2000-2002”. Acta Agraria Debreceniensis, no. 13 (May 4, 2004): 96–99. Accessed April 30, 2024. https://ojs.lib.unideb.hu/actaagrar/article/view/3390.