Lien-Fa Lin and  Yung-Ming Li and  Fu-Shun Hsieh,  A Social Decision Support Mechanism for Group Purchasing.   journal   = {International Journal of Economics and Management Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2016, vol. 116(8). 2734 - 2742
    [viewed 19 January 2022]. Available from: https://publications.waset.org/pdf/10005137.