1. Akul Melita. Genetic disorders and diseases; 2007: p. 1–14 〈http://pharmaxchange.info/press/〉 [accessed 26.05.15]
2. Emma Ujak, Luka Binniyat. Northern Nigeria has World highest illiterate – World Bank. Retrieved from The Nigerian Voice; 2011. 〈file:///C:/Users/ASUS%20PC/Documents/project/Documents/Northern%20Nigeria%20Has%20World%20highest%20illiterate%20--%20World%20Bank.html〉 [assessed 16.01.15]
3. WHO; 2014 – 〈http://www.who.int/genomics/public/geneticdiseases/en/index2.html〉 (accessed 03.10.14)
4. WHO; 1996. Control of hereditary disorders: report of WHO scientific meeting.