Yu Li and  Jingwu He and  Yuexi Xiong,  Layout Design Optimization of Spars under Multiple Load Cases of the High-Aspect-Ratio Wing.   journal   = {International Journal of Aerospace and Mechanical Engineering}, [online]. World Academy of Science, Engineering and Technology.
    August 2017, vol. 130(10). 1630 - 1634
    [viewed 10 December 2019]. Available from: https://publications.waset.org/pdf/10007949.