1. Source: Addenda to the Annual Reports of the General Manager of the South African Railways and Harbours
2. Source: For Tables 1 and 2 Handbook of Agricultural Statistics (1904–1950) issued by the Department of Agricultural Economics and Marketing (1961) and agricultural ceusus reports of the Department of Statistics
3. Hattingh, H. S. 1969. Course in farming business, Bloemfontein, 15–25th July