Faruk Fırat Çalım and  Nurullah Karaca and  Hakan Tacettin Türker,  Out-of-Plane Free Vibrations of Circular Rods.   journal   = {International Journal of Civil and Environmental Engineering}, [online]. World Academy of Science, Engineering and Technology.
    May 2015, vol. 101(5). 812 - 815
    [viewed 05 December 2021]. Available from: https://publications.waset.org/pdf/10001326.