Li, Yiming, et al. “Mechanical Model for Double Side Self-Propelled Rolling Machine Based on Rigid and Flexible Contact Dynamics”. International Journal of Agricultural and Biological Engineering, vol. 15, no. 6, Dec. 2022, pp. 38-43, https://ijabe.migration.pkpps03.publicknowledgeproject.org/index.php/ijabe/article/view/6485.