University of Pretoria. Forestry and Agricultural Biotechnology Institute; University of Pretoria. FABI(Forestry and Agricultural Biotechnology Institute, University of Pretoria, 1998)
Nakhumwa, T.O. (Teddie Oliver); Hassan, Rashid M.; Kirsten, Johann F.; Ng'ong'ola, D.H.(Agricultural Economics Association of South Africa, 1999-09)