Ami Kim and  Oubong Gwun and  Juwhan Song,  3D Model Retrieval based on Normal Vector Interpolation Method.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    September 2009, vol. 33(9). 621 - 624
    [viewed 22 January 2020]. Available from: https://publications.waset.org/pdf/5344.