Durand, Anette M.; Giesecke, W.H.; Barnard, Marie-Luise; Van der Walt, Martha L.; Steyn, Helena C.(Published by the Government Printer, Pretoria., 1990)
Kellerman, T. Stephanus; Marasas, Walter F.O. (Walter Friedrich Otto); Thiel, P.G.; Gelderblom, W.C.A.; Cawood, M.(Published by the Government Printer, Pretoria., 1990)