Hongxin, Liu, Guo Lifeng, Fu Lulu, and Tang Shifa. 2015. “Study on Multi-Size Seed-Metering Device for Vertical Plate Soybean Precision Planter”. International Journal of Agricultural and Biological Engineering 8 (1). Beijing, China:1-8. https://ijabe.org/index.php/ijabe/article/view/925.