Tham khảo Nhóm_ngôn_ngữ_Maa

  1. Nordhoff, Sebastian; Hammarström, Harald; Forkel, Robert; Haspelmath, Martin biên tập (2013). “Ongamo–Maa”. Glottolog. Leipzig: Max Planck Institute for Evolutionary Anthropology. Đã bỏ qua tham số không rõ |chapterurl= (trợ giúp)
  2. Vossen, Rainer and Franz Rottland. 1989. The historical reconstruction of Proto-Ongamo-Maa: phonology and vocabulary. In Bender, M. L. (ed.), Topics in Nilo-Saharan linguistics, 181-217. Hamburg: Helmut Buske Verlag.
  • Heine, Bernd & Vossen, Rainer (1980) 'The Kore of Lamu: A contribution to Maa dialectology', Afrika und übersee, 62, 272–288.
  • Vossen, Rainer (1982) The Eastern Nilotes: Linguistic and Historical Reconstructions. Berlin: Dietrich Reimer Verlag. ISBN 3-496-00698-6.
  • Vossen, Rainer (1988) Towards a comparative study of the Maa dialects of Kenya and Tanzania (Nilo-Saharan 2.) Hamburg: Helmut Buske Verlag.
  • Sommer, Gabriele (1992) 'A survey on language death in Africa', in Brenzinger, Matthias (ed.) Language Death: Factual and Theoretical Explorations with Special Reference to East Africa. Berlin/New York: Mouton de Gruyter, pp. 301–417.