REFERENCES
- Heyck H: Der Kopfschmerz: Differentialdiagnostik und Therapie für die Praxis. Ed 3. Stuttgart, Germany, Georg Thieme Verlag, 1964
- Wolff HG: Headache and Other Head Pain. Ed 2. New York, Oxford University Press, Inc, 1963
- Kunkle EC, Wolff HG: Headache. In Baker AB (Editor): Clinical Neurology. New York, Medical Division, Harper & Row, Publishers, 1955, chap 8
- Blumenthal LS: Introduction to headache. In Vinken PG, Bruyn GW (Editors): Handbook of Clinical Neurology. Amsterdam, North-Holland Publishing Co, 1968, vol 5, chap 1
- Classification of headache. JAMA 179: 717, 1962