Chunlin, Xu, et al. “Optimization of Working Parameters for Puddling and Flatting Machine in Paddy Field”. International Journal of Agricultural and Biological Engineering, vol. 9, no. 3, May 2016, pp. 88-96, https://www.ijabe.migration.pkpps06.publicknowledgeproject.org/index.php/ijabe/article/view/1608.