Burja C. and  Burja V.,  The Sustainable Value Model: Comparative Analysis Romania and EU.   journal   = {International Journal of Economics and Management Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2010, vol. 42(6). 737 - 741
    [viewed 19 October 2019]. Available from: https://publications.waset.org/pdf/9839.