TY  - RPRT
TI  - Multi-centre versus single-centre trials in migraine.
AU  - C Hedman
AU  - A R Andersen
AU  - J Olesen
PY  - 1987
DO  - 10.1159/000110119
UR  - https://pubmed.ncbi.nlm.nih.gov/3683713/
ID  - 3683713
ER  -