@article{mahmoud_el-shehawy_atta_2019,  title={Positron annihilation spectroscopy of chain-end-functionalized polystyrenes with definite numbers of benzyl alcohol and perfluorooctyl groups},  volume={29},  ISSN={0104-1428},  url={https://doi.org/10.1590/0104-1428.04619},  DOI={10.1590/0104-1428.04619},  number={4},  journal={Polímeros},  publisher={Associação Brasileira de Polímeros},  author={Mahmoud, Kamal Reyad and El-Shehawy, Ashraf and Atta, Hoda},  year={2019},  pages={e2019046} }