Yin, Xiang, et al. “Development and Evaluation of a Low-Cost Precision Seeding Control System for a Corn Drill”. International Journal of Agricultural and Biological Engineering, vol. 11, no. 5, Sept. 2018, pp. 95-99, https://ijabe.migration.pkpps03.publicknowledgeproject.org/index.php/ijabe/article/view/3369.