M. Amiri,  Investigation of Stability of Functionally Graded Material when Encountering Periodic Loading.   journal   = {International Journal of Mechanical and Mechatronics Engineering}, [online]. World Academy of Science, Engineering and Technology.
    September 2016, vol. 115(7). 1347 - 1353
    [viewed 25 April 2024]. Available from: https://publications.waset.org/pdf/10005711.