Anonymous; Steyn, P.J.J.; Bigalke, R.D.; Cameron, Colin McKenzie; Gilchrist, Frances M.C.; Morren, A.J.; Verwoerd, Daniel Wynand; Walker, Jane B.; Verster, Anna Johanna Maria(Pretoria : The Government Printer, 1981)
Anonymous; 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.(Published by The Government Printer, Pretoria, 1981)