Karam Y. Maalawi,  Buckling Optimization of Radially-Graded, Thin-Walled, Long Cylinders under External Pressure.   journal   = {International Journal of Mechanical and Mechatronics Engineering}, [online]. World Academy of Science, Engineering and Technology.
    September 2009, vol. 33(9). 1088 - 1095
    [viewed 25 April 2024]. Available from: https://publications.waset.org/pdf/361.