1. United Nations. 2007. World Population Prospects 2006.
2. UNICEF. Young child survival and development [updated 2009; cited 2009 Oct 5]. Available from: http://www.unicef.org/childsurvival/index.html .
3. World Bank. 2008. World Development Indicators 2008, data for 2005.
4. Lim SS, Stein DB, Charrow A, Murray CJL. Tracking progress towards universal childhood immunisation and the impact of global initiatives: a systematic analysis of three-dose diphtheria, tetanus, and pertussis immunisation coverage. Lancet. 2008;372(9655):2031–46.
5. Data source: United Nations [data on the Internet]. 2009. World Population Prospects 2008.