1. Adeola A. O. Ibekwe C. 2003. 317-25.
2. Ainge L Brown N 2004. US Agency for International Development. 15-35. http://terrysunderland.com/_asset/berkas/The_Key_Non-Timber_Forest_Products_of_Central_Africa:_State_of_the_Knowledge-190611.pdf
3. Anegbeh P. O. Tchoundjeu Z. Iruka C. G. Nkirika C. N. 2005. 6119-125. http://www.ajol.info/viewarticle.php?jid=12&id=24351&layout=abstract
4. Asaah E. K. Tchoundjeu Z. Atangana A. R. 2003. 1251-256. http://www.world-food.net
5. Dolor D. E. Ehondor N. Odiete L. 2010. 4311-18. http://www.agriculturaits.czu.cz