Buntheng Chhorn and  WooYoung Jung,  Dynamics Analyses of Swing Structure Subject to Rotational Forces.   journal   = {International Journal of Civil and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2018, vol. 134(2). 119 - 122
    [viewed 31 May 2020]. Available from: https://publications.waset.org/pdf/10008548.