1. Abel, A., and D. J. Macht: TWO cristalline pharmacological agents obtained from the tropical toad Bufo agua. J. Pharmacol. exp. Ther. 3, 319–377 (1912).
2. Adam, K. R., and C. Weiss: The occurrence of 5-hydroxytryptamine in Scorpion venom. J. exp. Biol. 35, 39–42 (1958).
3. Adam, K. R., and C. Weiss: Distribution of 5-hydroxytryptamine in Scorpion venoms. Nature (Lond.) 183, 1398–1399 (1959).
4. Adam, K. R., and C. Weiss: Scorpion venom. Z. Tropenmed. u. Parasit. 10, 334–339 (1959 a).
5. Andrew, A.: A study of the developmental relationship between enterochromaffin cells and the neural crest. J. Embryol. exp. Morph. 11, 307–324 (1963).