Muhammad E. Rahman and  Paul J. Fanning,  An Examination of Backing Effects on Ratings for Masonry Arch Bridges.   journal   = {International Journal of Civil and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    December 2010, vol. 48(12). 386 - 388
    [viewed 21 October 2019]. Available from: https://publications.waset.org/pdf/6549.