Hisham Nuri Akrim and  Abubaker Edkymish and  Nissreen Gryani,  The Efficiency of Irrigation System and Nitrogen Fixation for inoculated Soybeans by using N15 Tracer Techniques.   journal   = {International Journal of Agricultural and Biosystems Engineering}, [online]. World Academy of Science, Engineering and Technology.
    April 2012, vol. 64(4). 118 - 123
    [viewed 25 April 2024]. Available from: https://publications.waset.org/pdf/6779.