1. Arnold, H. L., 1968. Poisonous Plants of Hawaii. C. E. Tuttle Co., Rutland. 71 p.
2. Barrau, J. 1962. Observations et travaux recents sur les vegetaux hallucinogenes de la Nouvelle-Guinee. J. D’Agr. Trop. Botan. Appl.9: 245.
3. Brooker, S. G. & R. C. Cooper. 1961. New Zealand Medicinal Plants. Auckland. 46 p.
4. Burkill, I. H. & C. S. Crosby. 1901. The Flora of Vava’u. J. Linn Soc. (Bot.)35: 20.
5. Castenada, C. 1968. The Teachings of Don Juan. Univ. Calif. Press, Berkeley. 196 p.