Jinwu, Wang, et al. “Virtual Simulation Analysis and Verification of Seed-Filling Mechanism for Dipper Hill-Drop Precision Direct Rice Seeder”. International Journal of Agricultural and Biological Engineering, vol. 10, no. 6, Nov. 2017, pp. 77-85, https://ijabe.migration.pkpps06.publicknowledgeproject.org/index.php/ijabe/article/view/2981.