M. Karami Khorramabadi and  A. R. Nezamabadi,  Vibration Analysis of Functionally Graded Engesser- Timoshenko Beams Subjected to Axial Load Located on a Continuous Elastic Foundation.   journal   = {International Journal of Mechanical and Mechatronics Engineering}, [online]. World Academy of Science, Engineering and Technology.
    October 2014, vol. 94(10). 1723 - 1726
    [viewed 20 February 2020]. Available from: https://publications.waset.org/pdf/9999602.