1. World Health Organization: World Health Report 2004: changing history. 2004, Geneva: WHO
2. World Health Organization: Weekly epidemiological record. 1998, 27 (73): 201-208.
3. World Health Organization: Weekly epidemiological record. 2006, 31 (81): 297-308.
4. World Health Organization: Communicable diseases prevention and control: new, emerging, and re-emerging infectious diseases. 1995, WHA48.13. Geneva: WHO
5. World Health Organization Regional Office for Africa: Cholera control: a challenge in the African Region. Communicable Diseases Epidemiological Report. 2004, Brazzaville: WHO/AFRO