↑ Maddieson, Ian. 2008. Absence of Common Consonants. In: Haspelmath, Martin & Dryer, Matthew S. & Gil, David & Comrie, Bernard (eds.) The World Atlas of Language Structures Online. Munich: Max Planck Digital Library, chapter 18. Available online at http://wals.info/feature/18. Accessed on 2008-09-15.
↑ Ferguson (1963) 'Assumptions about nasals', in Greenberg (ed.) Universals of Language, pp 50-60.
Ladefoged, Peter (1996). The Sounds of the World's Languages. Oxford: Blackwell. ISBN 0-631-19814-8. Unknown parameter |coauthors= ignored (|author= suggested) (help)
Saout, J. le (1973) 'Languages sans consonnes nasales', Annales de l Université d'Abidjan, H, 6, 1, 179-205.
Williamson, Kay (1989) 'Niger-Congo overview', in Bendor-Samuel & Hartell (eds.) The Niger-Congo Languages, 3-45.
