Schulman Elliott A, Lipton Richard, Peterlin B Lee, Levin Morris, Grosberg Brian M
Neurology, Jefferson School of Medicine and Lankenau Institute for Medical Research, Lancaster Avenue, Wynnewood, PA 19096, USA.
Headache. 2010 Nov;50(10):1637-9. doi: 10.1111/j.1526-4610.2010.01794.x.