TY  - JOUR 
T1  - Botulinum toxin type A wear-off phenomenon in chronic migraine patients: how long does the maximum efficiency last?
JO  - Arquivos de Neuro-Psiquiatria
A1  - PAK, Aygul Tantik
A1  - ÜSTÜN, İsmet
A1  - SENGUL, Yildizhan
SN  - 0004-282X
UL  - 10.1590/0004-282X-ANP-2020-0542
VL  - 79 
Y1  - 2021
PB  - Brasil 
ER  -