Roberto Sabatini and  Alessandro Gardi and  Mark A. Richardson,  LIDAR Obstacle Warning and Avoidance System for Unmanned Aircraft.   journal   = {International Journal of Computer and Systems Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2014, vol. 88(4). 711 - 722
    [viewed 11 May 2021]. Available from: https://publications.waset.org/pdf/9997995.