Nwosu, O. C., and E. Ugwuerua. “Rotational Presidency and Ethnic Sentiments in Nigeria: An Analysis of President Obasanjo and Yar’Adua’s Regimes, 1999- 2010”. The International Journal of Humanities & Social Studies, vol. 2, no. 11, Nov. 2014, https://internationaljournalcorner.com/index.php/theijhss/article/view/140742.