References
- Hanbury Daniel. Science Papers. London 1876
- Siering Otto. Deutsche Apotheker-Zeitung 1957; 97: 791–792
- Staner P., Boutique R. Plantes médicinales indigènes du Congo Belge. Bruxelles 1937
- Watt J. M., Breyer-Brandwijk M. G. The medicinal and poisonous plants of Southern Africa. Edinburgh 1932
- National Geographic Magazine. 1917; 173, (many illustrations)