* Sidiyasa, K., 1998. Taxonomy, phylogeny, and wood anatomy of Alstonia (Apocynaceae). Blumea Supplement 11. Rijksherbarium / Hortus Botanicus, Leiden University, Leiden, Netherlands. 230 pp.
* World Agroforestry Centre, undated. Agroforestree Database. [Internet] World Agroforestry Centre (ICRAF), Nairobi, Kenya. http://www.worldagroforestry.org/ Sites/TreeDBS/ aft.asp. January 2005.
== Other references ==