Alaa Hussein Wadi,  Effect of a Gravel Bed Flocculator on the Efficiency of a Low Cost Water Treatment Plants.   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    February 2010, vol. 38(2). 75 - 80
    [viewed 24 April 2024]. Available from: https://publications.waset.org/pdf/2790.