1. Ziegler, M. R., and Doeden, D. (1958).
2. Science, Builbring, E., and Lin, R. C. Y. (1958). J. Physiol. (Lond.), 140, 381. Collier, H. 0. Lewis.
3. Pergamon In 5-Hydroxytryptamine;J.,1958
4. Erspamer, V. (1952). Ric. Scd., 22, 694.
5. Haverback, B J., and Davidson, J. D. (1958). 35, 570.