WASET
    M. Dachyar and  Yudavedito,  Portfolio Simulation in GSM Cellular Telecommunication Industry for Company's Decision and Policies Making.   journal   = {International Journal of Economics and Management Engineering}, [online]. World Academy of Science, Engineering and Technology.
    September 2011, vol. 57(9). 1141 - 1144
    [viewed 26 April 2024]. Available from: https://publications.waset.org/pdf/5183.