Chahid K. Ghaddar,  Unconventional Calculus Spreadsheet Functions .   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    March 2016, vol. 112(4). 194 - 200
    [viewed 24 September 2020]. Available from: https://publications.waset.org/pdf/10004374.