TY  - RPRT
TI  - Solved and unsolved headache problems.
AU  - J W Lance
PY  - 1991
DO  - 10.1111/j.1526-4610.1991.hed3107439.x
UR  - https://pubmed.ncbi.nlm.nih.gov/1774158/
ID  - 1774158
ER  -