Mostefa Kara, E., M. Meghachou, and N. Aboubekr. “Contribution of Particles Size Ranges to Sand Friction”. Engineering, Technology & Applied Science Research 3, no. 4 (August 11, 2013): 497–501. Accessed June 26, 2022. https://etasr.com/index.php/ETASR/article/view/361.