WASET
    Tim D. Sass and  Pe and  Leed,  Solar Panel Installations on Existing Structures.   journal   = {International Journal of Civil and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    April 2013, vol. 76(4). 308 - 313
    [viewed 29 March 2024]. Available from: https://publications.waset.org/pdf/14814.