Chia-Hau Liu and  Tai-Yue Wang,  An AK-Chart for the Non-Normal Data.   journal   = {International Journal of Economics and Management Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2014, vol. 91(7). 1107 - 1112
    [viewed 16 July 2020]. Available from: https://publications.waset.org/pdf/9998681.