1. Herzfeld, U., Christian, W., Ronge, J., Wittgen, M.: Parameters for estimating cerebral function after long term therapy with hydergine. Ärztl. Forsch.26, 215 (1972)
2. Oldendorf, W.H.: Cerebral blood flow measurements. In: Recent advances in nuclear medicine, p. 44, New York: Appleton-Century-Crofts 1966
3. Posner, J.B.: Newer techniques of cerebral blood flow measurements. Stroke3, 227 (1972)
4. Ingvar, D.H.: The focal cerebrovascular lesion. A survey of recent studies with isotope techniques and their clinical implications. In: Cerebral circulation and stroke, p. 129. New York: Springer-Verlag 1971
5. Triboletti, F., Ferri, H.: Hydergine for treatment of symptoms of cerebrovascular insufficiency. Curr. ther. Res.11, 609 (1969)