Van der Heyden et al., 1999. In: Tainton, N. (Ed.), Veld Management in South Africa. University of Natal Press, Pietermarizburg, South Africa, pp. 80-85

Van der Heyden, F.; Stock, W. D., 1999. Karoo Shrubs. In: Tainton, N. (Ed.), Veld Management in South Africa. University of Natal Press, Pietermarizburg, South Africa, pp. 80-85