WASET
    B. Daee and  H. M. El Naggar,  Application of Flexi-Wall in Noise Barriers Renewal.   journal   = {International Journal of Structural and Construction Engineering}, [online]. World Academy of Science, Engineering and Technology.
    July 2015, vol. 104(8). 967 - 972
    [viewed 11 May 2024]. Available from: https://publications.waset.org/pdf/10001844.