Abdullahi Jibrin and  Aishetu Abdulkadir,  Allometric Models for Biomass Estimation in Savanna Woodland Area, Niger State, Nigeria.   journal   = {International Journal of Geological and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2015, vol. 100(4). 283 - 291
    [viewed 23 September 2020]. Available from: https://publications.waset.org/pdf/10000945.