http://www.sil.org/africa/cameroun/bydomain/linguistics/archives/niellim_bagwell1992_1906_p.pdf (Publisher version)
Bagwell, R., & Bagwell, S. (1992). Enquete sociolinguistique de la langue Niellim (Lua) du moyen Chari, Tchad (N.A.). N'Djaména: SIL.