Nakhumwa, T.O. (Teddie Oliver); Hassan, Rashid M.; Kirsten, Johann F.; Ng'ong'ola, D.H.(Agricultural Economics Association of South Africa, 1999-09)
Doyer, O.T.; D'Haese, M.F.C. (Marijke); Kirsten, Johann F.; Van Rooyen, C.J. (Cornelius Johannes)(Agricultural Economics Association of South Africa, 2007-12)