Authors: Retief, E Van Wyk, AE

Citation: E. Retief et Ae. Van Wyk, The genus Ehretia (Boraginaceae : Ehretioideae) in southern Africa, BOTHALIA, 31(1), 2001, pp. 9-23

Authors: Botha, CJ Schultz, RA Van der Lugt, JJ Retief, E Labuschagne, L

Citation: Cj. Botha et al., Neurotoxicity in calves induced by the plant, Nierembergia hippomanica Miers var. violacea Millan in South Africa, ONDERST J V, 66(3), 1999, pp. 237-244

Authors: Retief, E Van Wyk, AE

Citation: E. Retief et Ae. Van Wyk, The genus Echium (Boraginaceae) in southern Africa, BOTHALIA, 28(2), 1998, pp. 167-177