“Modeling of Porosity Equation for Water Flow Through Packed Bed of Monosize Spherical Packing”. Journal of Engineering and Sustainable Development 15, no. 4 (December 1, 2011): 205–226. Accessed May 19, 2024. https://jeasd.uomustansiriyah.edu.iq/index.php/jeasd/article/view/1320.