1. ARIENS, E.J., J.M. VAN ROSSUM, and A.M. SIMONIS: Arzneimittel-Forsch. 6, 282 (1956)
2. AULICH, A., K. STOCK, and E. WESTERMANN: Life Sci. 6, 929 (1967)
3. BERGSTRöm, S., L.A. CARLSON, and L. ORö: Acta physiol. scand. 60, 170 (1964)
4. BURNS, J.J., K.I. COLVILLE, L.A. LINDSAY, and R.A. SALVADOR: J. Pharmacol. 144, 163 (1964)
5. BURNS, J.J. and L. LEMBERGER: Fed. Proc. 24, 298 (1965)