M. M. Ali and  Ahmed Al-Ani and  Derek Eamus and  Daniel K. Y. Tan,  Image-Based (RBG) Technique for Estimating Phosphorus Levels of Crops.   journal   = {International Journal of Agricultural and Biosystems Engineering}, [online]. World Academy of Science, Engineering and Technology.
    October 2015, vol. 106(10). 1125 - 1128
    [viewed 07 May 2024]. Available from: https://publications.waset.org/pdf/10002856.