Pulak Swain and  A. K. Ojha,  Multi-Criteria Based Robust Markowitz Model under Box Uncertainty.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    January 2021, vol. 170(2). 14 - 17
    [viewed 22 April 2021]. Available from: https://publications.waset.org/pdf/10011830.