@article{ataabadi_khedmati_ataabadi_2014,  title={Free vibration analysis of orthtropic thin cylindrical shells with variable thickness by using spline functions},  volume={11},  ISSN={1679-7825},  url={https://doi.org/10.1590/S1679-78252014001200001},  DOI={10.1590/S1679-78252014001200001},  number={12},  journal={Latin American Journal of Solids and Structures},  publisher={Individual owner},  author={Ataabadi, Pouria Bahrami and Khedmati, Mohammad Reza and Ataabadi, Mostafa Bahrami},  year={2014},  pages={2099–2121} }