1. Central Intelligence Agency, “Nigeria,” in The World Factbook. 2011.
2. FOS. Federal Office of Statistics; 1989.
3. Nigeria Fact Sheet (published by: Nigeria High Commission, New Delhi); 2001:3.
4. V.A.OyenugaAgriculture in Nigeria1967Food and Agriculture Organization of the United Nations). FAORome, Italy308
5. DuPont HL, Chapell CL, Sterling CR, Okhuysen PC, Rose JB, Jakubowski W. The infectivity of Cryptosporidium parvum in healthy volunteers. N Engl J Med 1195;332:855–859.