Katleho D. Makatjane and  Kalebe M. Kalebe,  Modelling Conditional Volatility of Saving Rate by a Time-Varying Parameter Model.   journal   = {International Journal of Economics and Management Engineering}, [online]. World Academy of Science, Engineering and Technology.
    August 2018, vol. 141(9). 1171 - 1174
    [viewed 27 April 2024]. Available from: https://publications.waset.org/pdf/10009468.