1. Anti-Corruption Trust of Southern Africa 2010 Mini-assessment report: Corruption by traffic police officers and vehicle drivers in Botswana, Namibia and Zimbabwe http://www.kubatana.net/docs/demgg/act-sa_traffic_police_corruption_101111.pdf
2. Ayee J 2007 Building Tax Compliance through Reciprocity with Government
3. Baer K 2003 Taxing the informal sector http://web.worldbank.org/wbsite/external/topics/extpublicsectorandgovernance/extpublicfinance/exttpa/0,,contentmdk:20234805~iscurl:y~pagepk:148956~pipk:216618~thesitepk:390367,00.html
4. The VAT in Developing and Transitional Countries
5. Bird RM Wallace S 2003 Is it really so hard to tax the hard-to-tax? The context and role of presumptive taxes ITP Paper 0307