1. Willis, J. C., A Dictionary of the Flowering Plants and Ferns. Cambridge University, 1973, p. 771.
2. Schultes, R. E. and Holmstedt, B., Lloydia, 1971, 34, 61.
3. Franca, N. C., Gottlieb, O. R. and Rosa, B. de P., Phytochemistry, 1975, 14, 590.
4. Gottlieb, O. R., Ciência e Cultura, 1980, 32, 18.