H. Bouadi and  M. Bouchoucha and  M. Tadjine,  Sliding Mode Control Based on Backstepping Approach for an UAV Type-Quadrotor.   journal   = {International Journal of Mechanical and Mechatronics Engineering}, [online]. World Academy of Science, Engineering and Technology.
    February 2007, vol. 2(2). 39 - 44
    [viewed 09 August 2020]. Available from: https://publications.waset.org/pdf/11524.