The Niger-Kordofanian language family was proposed by Joseph Greenberg in his 1966 book Languages of Africa.
The family is claimed to include the Niger-Congo and Kordofanian families. Most historical linguists consider the connection between these two language groups a plausible but still unproven hypothesis.
References
- Joseph Greenberg, The Languages of Africa. Indiana Univ. Press (1966).
- Bernd Heine and Derek Nurse , African Languages - An Introduction. Cambridge Univ. press (2000)
- John Bendor-Samuel , The Niger-Congo Languages — A classification and description of Africa's largest language family, University Press of America (1989).