@article{üstün özek_2022,  title={A study on the correlation between pain frequency and severity and vitamin B12 levels in episodic and chronic migraine},  volume={80},  ISSN={0004-282X},  url={https://doi.org/10.1590/0004-282X-ANP-2021-0192},  DOI={10.1590/0004-282X-ANP-2021-0192},  number={6},  journal={Arquivos de Neuro-Psiquiatria},  publisher={Academia Brasileira de Neurologia - ABNEURO},  author={Üstün Özek, Sibel},  year={2022},  month={Jun},  pages={586–592} }