Ahmad Attiq Al-Ogaibi and  Ahmad Sharieh and  Moh’d Belal Al-Zoubi and  R. Bremananth,  A Robust Method for Finding Nearest-Neighbor using Hexagon Cells.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    November 2014, vol. 85(1). 38 - 45
    [viewed 25 September 2020]. Available from: https://publications.waset.org/pdf/9997211.