1. Adebayo AA 1997. Factor analysis of forest floor variability in a savanna wood land of south western Nigeria. Global Journal of Pure and Applied Sciences 3(2):255-263.
2. Asuzu IU Onu UO 1994. Anthelmintic activity of the ethanolic extract of Piliostigma thonningii bark in Ascaridia galli infected chickens. Fitoterapia 65(4):291-297; 17 ref.
3. Bekele-Tesemma A Birnie A Tengnas B 1993. Useful trees and shrubs for Ethiopia. Regional Soil Conservation Unit (RSCU) Ethiopia: Swedish International Development Authority (SIDA).
4. Burkill HM 1995. The useful plants of West Tropical Africa. Vol. 3: Families J-L. Richmond UK: Royal Botanic Gardens Kew.
5. Coates-Palgrave K 1996. Trees of Southern Africa. Cape Town South Africa: C. S. Struik Publishers.