1. Hanington, E., in Background to Migraine, Second Migraine Symp. (edit. by Smith, R.) (Heinemann, London, 1967).
2. Smith, I., Kellow, A. H., and Hanington, E., in Background to Migraine, Third Migraine Symp. (edit. by Cochrane, A. L.), 134 (Heinemann, London, 1970).
3. Oates, J. A., in Methods of Medical Research (edit. by Quastel, J. H.), 9, 169 (Year Book Medical Publications, Chicago, 1961).
4. Karoum, F., Ruthven, C. R. J., and Sandler, M., Clin. Chim. Acta, 20, 427 (1968).
5. Lemberger, L., Klutch, A., and Kuntzmann, R., J. Pharmacol. Exp. Ther., 153, 183 (1966).