Ebrahim, Ismail Z, Ayman Hafiz Amer Eissa, and Yingkuan Wang. 2010. “Vertical Brush Seed Metering Device for Sweet Sugar Beet Planter”. International Journal of Agricultural and Biological Engineering 3 (1). Beijing, China:26-37. https://www.ijabe.org/index.php/ijabe/article/view/202.