@article{pak_üstün_sengul_2021,  title={Botulinum toxin type A wear-off phenomenon in chronic migraine patients: how long does the maximum efficiency last?},  volume={79},  ISSN={0004-282X},  url={https://doi.org/10.1590/0004-282X-ANP-2020-0542},  DOI={10.1590/0004-282X-ANP-2020-0542},  number={10},  journal={Arquivos de Neuro-Psiquiatria},  publisher={Academia Brasileira de Neurologia - ABNEURO},  author={PAK, Aygul Tantik and ÜSTÜN, İsmet and SENGUL, Yildizhan},  year={2021},  month={Oct},  pages={886–890} }