De Kock, V.E.; Steyn, P.J.J; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.(Pretoria : Government Printer, 1978)
Steyn, P.J.J; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.(Pretoria : The Government Printer, 1978)
De Kock, V.E.; Steyn, P.J.J; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verster, Anna J.M.; Verwoerd, Daniel Wynand; Walker, Jane B.(Pretoria : The Government Printer, 1978)