1. Integration among unequals: The Southern African Customs Union and Development;Cobbe;World Development,1980
2. The normative theory of international trade;Corden,1984
3. The Economics of the Customs Union between Botswana, Lesotho, Swaziland, and South Africa;Ettinger,1973
4. Botswana's membership of the Southern African Customs Union;Hudson,1981
5. International Monetary Fund, International Financial Statistics (Washington, DC: IMF, various years).