Jamal A. Gledan and  Akrm H. Algnin ,  Precision Assessment of the Orthometric Heights Determination in the Northern Part of Libya .   journal   = {International Journal of Geological and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    February 2014, vol. 87(3). 268 - 272
    [viewed 26 April 2024]. Available from: https://publications.waset.org/pdf/9997698.