TY  - RPRT
TI  - How many different headaches do you have?
AU  - W F Laughey
AU  - E A MacGregor
AU  - M I Wilkinson
PY  - 1993
DO  - 10.1046/j.1468-2982.1993.1302136.x
UR  - https://pubmed.ncbi.nlm.nih.gov/8495458/
ID  - 8495458
ER  -