F. Z. Aliyat and  B. Ben Messaoud and  L. Nassiri and  E. Bouiamrine and  J. Ibijbijen,  Assessment of the Biological Nitrogen Fixation in Soybean Sown in Different Types of Moroccan Soils.   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    October 2018, vol. 143(11). 719 - 722
    [viewed 04 August 2020]. Available from: https://publications.waset.org/pdf/10009807.