J. Rizk and  M. H. Nagrial,  Impact of Reflectors on Solar Energy Systems.   journal   = {International Journal of Energy and Power Engineering}, [online]. World Academy of Science, Engineering and Technology.
    May 2008, vol. 17(5). 743 - 747
    [viewed 16 October 2019]. Available from: https://publications.waset.org/pdf/2761.