Abeer Samy and  Oliver C. Saavedra Valeriano and  Abdelazim Negm,  Variability of Hydrological Modeling of the Blue Nile.   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    February 2015, vol. 99(3). 225 - 229
    [viewed 12 July 2020]. Available from: https://publications.waset.org/pdf/10000744.