Fan, Chenlong, et al. “Development and Performance Evaluation of the Electric-Hydraulic Concave Clearance Control System Based on Maize Feed Rate Monitoring”. International Journal of Agricultural and Biological Engineering, vol. 15, no. 2, Apr. 2022, pp. 156-64, https://ijabe.migration.pkpps03.publicknowledgeproject.org/index.php/ijabe/article/view/6369.