1. Akinlabi, A. (2000). Sonorant nasalization in Yorùbádeverbal nouns. Ms., Rutgers University.
2. Aziza, R. (2010). Urhobo phonology. In O. Yusuf (Ed.), Basic linguistics for Nigerian languages (pp. 278-294). Shebiotimo Publications.
3. Chomsky, N., & Halle, M. (1968). The sound pattern of English. Harper & Row.
4. Clark, J., & Yallop, C. (2000). An introduction to phonetics and phonology. Blackwell Publishers.
5. Crystal, D. (2008). A dictionary of linguistics and phonetics. (6th ed.). Blackwell Publishers.
6. Czaykowska-Higgins, E., Dobrovolsky, M., & Katamba, F. (2011). Phonology: The function and patterning of sounds. In W. O’Grady, J. Archibald, & F. Katamba (Eds.), Contemporary linguistics: An introduction. (2nd edn.) (pp. 59-115). Pearson Education Limited.
7. Emenanjo, E. N. (2015). A grammar of contemporary Igbo. Port Harcourt, Nigeria: University of Port Harcourt Press.
8. Enwere, O. B. (2018). Head-complement relations in Igbo: The Mbaise example. A PhD dissertation, University of Port Harcourt.
9. Goldsmith, J. (1976). Autosegmental phonology. Indiana University Linguistics Club.
10. Kager, R. (1999). Optimality theory. Cambridge University Press.
11. Maduagwu, G. O., & Dare, E. A. (2016). On phonological processes of dialect of Yorùbá: Spoken nasalization, vowel harmony and deletion in Ifẹ̀ in Bante region of Benin Republic. Knowledge Review, 34 (1), pp. 1-10.
12. McCarthy, J. (2002). A thematic guide to optimality theory. Cambridge University Press.
13. McCarthy, J. (2008). Doing optimality theory: Applying theory to data. Blackwell Publishers.
14. Oyebade, F. (2008). A course in phonology. (2nd edn.) Ijebu-Ode. Shebiotimo Publications.
15. Oyinloye, M. E. (2015). A constraint-based analysis of English loanwords in Yorùbá. M.A. dissertation, University of Ilorin.
16. Oyinloye, M. E. (2019). Nasal harmony in Yorùbá: A constraint-based analysis. 2nd PhD seminar paper, University of Ilorin.
17. Prince, A., & Smolensky, P. (1993). Optimality theory: Constraint interaction in generative grammar. Ms., Rutgers University.
18. Prince, A., & Smolensky, P. (2004). Optimality theory: Constraint interaction in generative grammar. Publishers.
19. Pulleyblank, D. (1997). Optimality theory and features. In D. Archangeli, & T. Langendoen (Eds.), Optimality theory: An overview (pp. 59-101). Blackwell Publishers.