1. Experimental caffeine withdrawal headache.;Dreisbach RH;J Pharmacol Exp Ther,1940
2. Development of Tolerance to Ergot Alkaloids in a Patient with Unusually Severe Migraine
3. Observations on the development of tolerance during prolonged oral administration of dihydroergocornine.;Moister FC;J Pharmacol Exp Ther,1949
4. Headache: with special reference to the excessive use of ergotamine preparations and withdrawal effects.;Peters GA;Mayo Clin Proc,1951
5. Ergotamine tolerance in patients with migraine.;Friedman AP;N Engl J Med,1955