Anas M. Fares and  A. Touqan,  Effect of Shear Wall Openings on the Fundamental Period of Shear Wall Structures.   journal   = {International Journal of Civil and Architectural Engineering}, [online]. World Academy of Science, Engineering and Technology.
     2019, vol. 145(1). 18 - 26
    [viewed 17 October 2019]. Available from: https://publications.waset.org/pdf/10009934.