TY  - JOUR 
T1  - A study on the correlation between pain frequency and severity and vitamin B12 levels in episodic and chronic migraine
JO  - Arquivos de Neuro-Psiquiatria
A1  - Üstün Özek, Sibel
SN  - 0004-282X
UL  - 10.1590/0004-282X-ANP-2021-0192
VL  - 80 
Y1  - 2022
PB  - Brasil 
ER  -