Shi, Linrong, et al. “Investigation of Interaction Effect Between Static and Rolling Friction of Corn Kernels on Repose Formation by DEM”. International Journal of Agricultural and Biological Engineering, vol. 14, no. 5, Oct. 2021, pp. 238-46, https://ijabe.migration.pkpps03.publicknowledgeproject.org/index.php/ijabe/article/view/4357.