Xun Ge and  Jingju Qian,  Some Investigations on Higher Mathematics Scores for Chinese University Student.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    July 2009, vol. 31(7). 538 - 541
    [viewed 17 April 2021]. Available from: https://publications.waset.org/pdf/13848.