1. Creese, R., Taylor, D. B., and Tilton, B., J. Pharmacol., 138, 8 (1963).
2. Taylor, D. B., Creese, R., and Scholes, N. W., J. Pharmacol., 144, 293 (1964).
3. Creese, R., and Taylor, D. B., Nature, 206, 310 (1965).
4. Hebb, C. O., Krnjević, K., and Silver, A., J. Physiol., 171, 504 (1964).
5. Waser, P., and Lüthi, U., Arch. Intern. Pharmacodyn., 112, 272 (1957).