Limin Zhao and  Xingfa Gu and  C. Tao Yu,  Modeling Directional Thermal Radiance Anisotropy for Urban Canopy.   journal   = {International Journal of Physical and Mathematical Sciences}, [online]. World Academy of Science, Engineering and Technology.
    November 2011, vol. 59(11). 1717 - 1720
    [viewed 25 January 2020]. Available from: https://publications.waset.org/pdf/15371.