1. Altschul, S. V. R., Ethnopharmacologic Search for Psychoactive Drugs: 307 (1967).
2. BARRAU, J, JOURNAL D'AGRICULTURE TROPICALE ET DE BOTANIQUE APPLIQUEE 9: 245 (1962).
3. BOUQUET, R.J., BULLETIN ON NARCOTICS 2 4: 14 (1950).
4. BUNGE, A, MEMOIRES DES SAVANTS ETRANGERS ST. PETERSBURG 7: 438 (1847).
5. COOPER, J. M., BUREAU OF AMERICAN ETHNOLOGY BULLETIN 143: 525 (1949).