Potgieter, Petrus H. and Rosinger, Elemér E. (2007): Is Economics Entering its Post-Witchcraft Era? Unpublished.
Potgieter, Petrus H. and Rosinger, Elemér E. (2007): Is Economics Entering its Post-Witchcraft Era? Unpublished.
Potgieter, Petrus H. (2010): Water and energy in South Africa – managing scarcity. Unpublished.
